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This manuscript presents research on the optoelectronic and energy transfer properties of conjugated polymer poly (N,N′-bis-4-butylphenyl-N,N'-bisphenyl)benzidine (poly-TPD) and laser dye Fluorol 7GA (F7GA) hybrid thin films prepared via solution blending technique. Various weight ratios of F7GA were added to a fixed concentration of poly-TPD to form homogeneous hybrids. The hybrid thin films were characterized using absorption and photoluminescence spectroscopy. The results showed enhanced absorption, widened optical bandgaps, slight blue-shifted emission, and decreased refractive index in the hybrid films compared to pristine poly-TPD. The significant spectral overlap between the emission spectrum of poly-TPD and the absorption spectrum of F7GA, allowing for efficient Förster resonance energy transfer. Parameters including efficiency, distance, lifetime, and probability of energy transfer were calculated to quantitatively analyze energy transfer. Modulation of F7GA content led to tunable emission colors across the visible spectrum. Overall, the successful energy transfer demonstrated in this study paves the way for exciting future directions in the field of poly-TPD/F7GA hybrid materials for advanced optoelectronic applications. [ABSTRACT FROM AUTHOR]

Amorphous thin films of SnO2, prepared by a vacuum evaporation technique under a pressure of 10− 5 mbar, are employed as electro-optical filters suitable for microwave, infrared, and visible light communication technologies. The filters perform as optical layers, exhibiting optical transitions within an energy band gap of 3.62 eV, with the band gap containing energy band tails of widths of 0.63 eV. In addition, dielectric dispersion analyses on the optical filters show their ideality for high k-gate dielectric applications. Wide tunability in the dielectric response is observed in these films. Moreover, analyses of the optical conductivity and terahertz cutoff frequency spectra have shown that SnO2 films exhibit resonance of optical signals suitable for infrared and visible light communication technology as well. When excited with infrared light of energy of 1.38 eV, the drift mobility and free hole concentration in these films reach 11.72 cm2/Vs and 2 × 1017 cm− 3, respectively. Furthermore, the device exhibits a negative resistance effect in the microwave range of 0.1–1.80 GHz, and terahertz cutoff frequency values in the range of 10 GHz − 48 THz. The features of the SnO2 electro-optical band filter make them attractive for communication technology extending from 5G/6G to IR and reaching visible light communications. [ABSTRACT FROM AUTHOR]

This study introduces a novel methodology for predicting photodetector responsivity, specifically targeting challenging materials like borophene. The synthesis of these materials faces substantial experimental complexities, necessitating reliable performance predictions before fabrication. To address this, a comprehensive approach leveraging advanced machine learning techniques, specifically artificial neural networks (ANN), is developed. Integration of X‐ray diffraction (XRD) and Raman spectra data into AI models enables efficient prediction of photodetector efficiency prior to device fabrication. The innovation lies in strategically incorporating Generative Adversarial Networks (GANs) for dataset augmentation, significantly expanding the dataset size and enhancing the robustness of the ANN model. Sensitivity analyses highlighted influential factors such as bias voltage and spectral coefficients, validating the approach and aligning with recent experimental findings. This methodology not only advances optoelectronics, but also holds promise for materials science and device engineering. Predictions for Wavelength‐Responsivity plots, considering borophene allotropes as active layers and n‐Si as substrates, show peaks around 300–400 nm, ranging from 0.04 to 0.36 AW−1 at bias voltages between 1 and 5 volts. These estimations assume a borophene layer thickness of approximately 1.6 nm and a radiation power intensity of 5000 µ Wcm−2. [ABSTRACT FROM AUTHOR]

Herein, we report the nonlinear refractive index and nonlinear absorption coefficient of anthraquinone dye (disperse blue 14)-doped polymer film using a facile Z-scan technique. The Z-scan studies were carried out using a semiconductor diode laser with a constant power output of 5 mW at a wavelength of 635 nm as the source of excitation. The Z-scan technique consists of closed and open aperture methods, which revealed the self-defocusing and reverse saturable absorption mechanisms based optical nonlinearity. The third-order nonlinear optical susceptibility (χ(3)) of dye-doped polymer film was estimated to be in the order of 10–5 esu. Optical limiting (OL) behaviour of the polymer film with different dye concentrations was performed under the same experimental conditions and found to be a low OL threshold of 1.45 × 102 W cm–2 at 0.04 mM dye concentration. Self-diffraction ring pattern of the polymer film was also noticed in the far field. The overall results found that the dye-doped polymer film is a potential material for photonics and optoelectronics applications. [ABSTRACT FROM AUTHOR]

Nanoparticles below 100 nm have sparked immense interest for their unique physical and chemical properties, separate from bulk materials. These particles have versatile applications in electronics, magnetism, optoelectronics, and electricity. This article overviews ongoing research on nanoparticle-based electronic devices and explores anticipated advancements. In electronics, nanoparticles are essential components for enhanced performance and functionality, promising breakthroughs in computing, telecommunications, and sensing. This work explores the groundbreaking potential of metal-based nanoparticles, such as ZnO NPs, Cu NPs, Al NPs, and Fe NPs, in various electronic device applications. It investigates different synthetic methods, including bottom–up, sol–gel, co-precipitation, hydrothermal, CVD, and green/biological method to enhance the effectiveness of these nanoparticles. The study briefly examines the efficiency of these nanoparticles for electronic device applications, and it extends their potential applications to areas such as data storage, sensors, protective coatings, energy storage, chemical industries, water treatment, fertilizers, and defense. Challenges include precise control of nanoparticle shape and arrangement, which researchers address to design new materials with controlled properties. The present work discusses the anticipated and emerging applications of nanoparticles, emphasizing their unique physical and chemical properties compared to bulk materials. Ongoing research explores their full potential, while manipulation techniques open doors to novel materials. The progress made underscores the immense possibilities of nanoparticle-based electronics. [ABSTRACT FROM AUTHOR]

The co-location of memory and processing is a core principle of neuromorphic computing. A local memory device for synaptic weight storage has long been recognized as an enabling element for large-scale, high-performance neuromorphic hardware. In this work, we demonstrate programmable superconducting synapses with integrated memories for use in superconducting optoelectronic neural systems. Superconducting nanowire single-photon detectors and Josephson junctions are combined into programmable synaptic circuits that exhibit single-photon sensitivity, memory cells with more than 400 internal states, leaky integration of input spike events, and 0.4 fJ programming energies (including cooling power). These results are attractive for implementing a variety of supervised and unsupervised learning algorithms and lay the foundation for a new hardware platform optimized for large-scale spiking network accelerators. [ABSTRACT FROM AUTHOR]

Low-dimension materials such as transition metal dichalcogenides (TMDCs) have received extensive research interest and investigation for electronic and optoelectronic applications. Due to their unique widely tunable band structures, they are good candidates for next-generation optoelectronic devices. Particularly, their photoluminescence properties, which are fundamental for optoelectronic applications, are highly sensitive to the nature of the band gap. Monolayer TMDCs in the room temperature range have presented a direct band gap behavior and bright photoluminescence. In this work, we investigate a popular TMDC material WSe2's photoluminescence performance using a Raman spectroscopy laser with temperature dependence. With temperature variation, the lattice constant and the band gap change dramatically, and thus the photoluminescence spectra are changed. By checking the photoluminescence spectra at different temperatures, we are able to reveal the nature of direct-to-indirect band gap in monolayer WSe2. We also implemented density function theory (DFT) simulations to computationally investigate the band gap of WSe2 to provide comprehensive evidence and confirm the experimental results. Our study suggests that monolayer WSe2 is at the transition boundary between the indirect and direct band gap at room temperature. This result provides insights into temperature-dependent optical transition in monolayer WSe2 for quantum control, and is important for cultivating the potential of monolayer WSe2 in thermally tunable optoelectronic devices operating at room temperature. [ABSTRACT FROM AUTHOR]

4,4-Difluoro-4-bora-3a,4a-diaza-sindacene (BODIPY) is a sort of photofunctional dye which possesses advantages including strong light-capturing property, high photon-resistance, etc. Meso-N substituted aza-BODIPY is a crucial derivative of BODIPY scaffold that has the favorable optical properties and a significant spectral redshift. The photophysical properties can be tuned by molecular design, and the attenuation path of the excited state energy release of absorbed light energy can be well controlled via structural modifications, enabling tailored application. It has been extensively employed in life medicine fields including fluorescence imaging diagnosis, photodynamic therapy photosensitizer and photothermal therapy reagent and so forth. Extensive research and review have been performed in these areas. However, BODIPYs/aza-BODIPYs have a significant role in energy, catalysis, optoelectronics, photo-responsive materials and other fields. Nevertheless, there are relatively few studies and reviews in these fields on the modification and application based on BODIPY/aza-BODIPY scaffold. Herein, in this review we summarized the application of BODIPY/aza-BODIPY in the aforementioned fields, with the molecular regulation of dye as the foundation and the utilization in the above fields as the objective, in the intention of providing inspiration for the exploration of innovative BODIPY/aza-BODIPY research in the field of light resource conversion and functional materials. [ABSTRACT FROM AUTHOR]

Layered two‐dimensional (2D) materials have garnered marvelous attention in diverse fields, including sensors, capacitors, nanocomposites and transistors, owing to their distinctive structural morphologies and superior physicochemical properties. Recently, layered quasi‐2D materials, especially layered bismuth oxyselenide (Bi2O2Se), are of particular interest, because of their different interlayer interactions from other layered 2D materials. On this basis, this material offers richer and more intriguing physics, including high electron mobility, sizeable bandgap, and remarkable thermal and chemical durability, rendering it an utterly prospective contender for use in advanced electronic and optoelectronic applications. Herein, this article reviews the recent advances related with Bi2O2Se. Initially, its structural characterization, band structure, and basic properties are briefly introduced. Further, the synthetic strategies for the preparation of Bi2O2Se are presented. Furthermore, the diverse applications of Bi2O2Se in the field of electronics and optoelectronics, photocatalytic, solar cells and sensing were summarized in detail. Ultimately, the challenges and future perspectives of Bi2O2Se are included. [ABSTRACT FROM AUTHOR]

Carbazole-based molecular units are ubiquitous in organic optoelectronic materials; however, the excited-state relaxation of these compounds is still underexplored. Here, we provide a detailed investigation of carbazole (Cz) and 3,6-di-tert-butylcarbazole (t-Bu-Cz) in organic solvents using femtosecond and nanosecond UV–Vis–NIR transient absorption spectroscopy, as well as time-resolved fluorescence experiments upon photoexcitation in the deep-UV range. The initially prepared Sx singlet state has a (sub-)picosecond lifetime and decays to the S1 state by internal conversion (IC). The S1 state exhibits absorption peaks at 350, 600 and 1100 nm and has a lifetime of 13–15 ns, which is weakly dependent on the solvent. Energy transfer from vibrationally hot S1 molecules (S1*) to the surrounding solvent molecules takes place with a time constant of 8–20 ps. The T1 triplet state is populated by intersystem crossing (ISC) from S1 with a typical quantum yield of 51–56% and shows a lifetime which is typically in the few microseconds regime. The S1 and T1 states of both carbazole compounds in solution are strongly quenched by O2. Two-photon excitation leads to the formation of a small amount of the respective radical cation. The influence of the tert-butyl substituents on the photophysics is relatively weak and mainly reflects itself in a small increase in the Stokes shift. The results provide important photophysical information for the interpretation of carbazole relaxation in more complex environments. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is considered to be one of the most explored and reliable sensing materials for UV detection due to its excellent properties, like a wide band gap and high exciton energy. Our current study on a photodetector based on tetrapodal ZnO (t-ZnO) reported an extremely high UV response of ~9200 for 394 nm UV illumination at 25 °C. The t-ZnO network structure and morphology were investigated using XRD and SEM. The sensor showed a UV/visible ratio of ~12 at 25 °C for 394 nm UV illumination and 443 nm visible illumination. By increasing the temperature, monotonic decreases in response and recovery time were observed. By increasing the bias voltage, the response time was found to decrease while the recovery time was increased. The maximum responsivity shifted to higher wavelengths from 394 nm to 400 nm by increasing the operating temperature from 25 °C to 100 °C. The t-ZnO networks exhibited gas-sensing performances at temperatures above 250 °C, and a maximum response of ~1.35 was recorded at 350 °C with a good repeatability and fast recovery in 16 s for 100 ppm of n-butanol vapor. This study demonstrated that t-ZnO networks are good biosensors that can be used for diverse biomedical applications like the sensing of VOCs (volatile organic compounds) and ultraviolet detection under a wide range of temperatures, and may find new possibilities in biosensing applications. [ABSTRACT FROM AUTHOR]

The advancement of nanoscience and material design in recent times has facilitated the creation of point-of-care devices for cancer diagnosis and biomolecule sensing. Exosomes (EXOs) facilitate the transfer of bioactive molecules between cancer cells and diverse cells in the local and distant microenvironments, thereby contributing to cancer progression and metastasis. Specifically, EXOs derived from cancer are likely to function as biomarkers for early cancer detection due to the genetic or signaling alterations they transport as payload within the cancer cells of origin. It has been verified that EXOs circulate steadily in bodily secretions and contain a variety of information that indicates the progression of the tumor. However, acquiring molecular information and interactions regarding EXOs has presented significant technical challenges due to their nanoscale nature and high heterogeneity. Colorimetry, surface plasmon resonance (SPR), fluorescence, and Raman scattering are examples of optical techniques utilized to quantify cancer exosomal biomarkers, including lipids, proteins, RNA, and DNA. Many optically active nanoparticles (NPs), predominantly carbon-based, inorganic, organic, and composite-based nanomaterials, have been employed in biosensing technology. The exceptional physical properties exhibited by nanomaterials, including carbon NPs, noble metal NPs, and magnetic NPs, have facilitated significant progress in the development of optical nanobiosensors intended for the detection of EXOs originating from tumors. Following a summary of the biogenesis, biological functions, and biomarker value of known EXOs, this article provides an update on the detection methodologies currently under investigation. In conclusion, we propose some potential enhancements to optical biosensors utilized in detecting EXO, utilizing various NP materials such as silicon NPs, graphene oxide (GO), metal NPs, and quantum dots (QDs). [ABSTRACT FROM AUTHOR]

Pulsed‐laser‐deposition (PLD) is used to deposit MoS2 thin films at substrate temperatures (Td) ranging from 25 to 700 °C. A Td = 500 °C is identified as the optimal temperature that yields MoS2 films consisting of highly‐crystallized 2H‐MoS2 phase with a strong (002) preferential orientation, a direct optical bandgap (Eg) of ∼1.4 eV and a strong photoresponse of ∼1500%. Raman spectroscopy revealed that the degree of vertical alignment of MoS2 layers in the films also reaches its maximum at Td = 500 °C. High‐resolution‐transmission‐electron‐microscopy has provided a clear‐cut evidence that the PLD‐MoS2 films predominantly consist of vertically aligned MoS2 layers over all the film thickness of ∼90 nm, enabling those "3D" films to behave as a direct‐bandgap "2D‐MoS2" with exceptional optoelectronic properties. Indeed, at Td = 500 °C, the PLD‐MoS2 based photodetectors (PDs) devices are shown to exhibit the highest responsivity (R) and detectivity (D*) values (125 mA W−1 and 9.2 × 109 Jones, respectively) ever reported for large area (≥ 1 cm2) MoS2‐based PDs operating at a voltage as low as 1 V. For the first time, a constant‐plus‐linear relationship between Eg, R, and D* of the PDs and the degree of vertical alignment of the MoS2 layers is established. Such a correlation is fundamental for the controlled growth of PLD‐MoS2 films and the tuning of their properties in view of their integration with standard large‐scale‐integration processing. [ABSTRACT FROM AUTHOR]

Zinc (Zn) has arisen as a significant suppressor of vacancy formation in halide perovskites, establishing its pivotal role in defect engineering for these materials. Herein, the Zn‐catalyzed vapor‐liquid‐solid (VLS) route is reported to render black‐phase CsPbI3 nanowires (NWs) operationally stable at room temperature. Based on first‐principle calculations, the doped Zn2+ can not only lead to the partial crystal lattice distortion but also reduce the formation energy (absolute value) from the black phase to the yellow phase, improving the stability of the desired black‐phase CsPbI3 NWs. A series of contrast tests further confirm the stabilization effect of the Zn‐doped strategy. Besides, the polarization‐sensitive characteristics of black‐phase CsPbI3 NWs are revealed. This work highlights the importance of phase stabilization engineering for CsPbI3 NWs and their potential applications in anisotropic optoelectronics. [ABSTRACT FROM AUTHOR]

2D transition metal dichalcogenides (TMDs) have emerged as a novel class of semiconductors with promising applications in optoelectronics, owing to their rich and tunable valley fine structure, known as valleytronics. Strain engineering in TMDs presents opportunities to tailor their valley fine structures and band alignment, which greatly expands the potential to investigate their intrinsic properties and improve device performance, thus opening a new field of straintronics. In this review, recent advances in strain‐engineered 2D TMDs are summarized, with a focus on new phenomena and applications enabled by precision tuning of valley physics. The underlying mechanisms and connections are delineated between strain‐induced modifications to the valley fine structures based on intravalley, intervalley, and interlayer band alignment in single and heterostructure TMDs. These insights allow targeted strain control strategies to be devised for optimizing optoelectronic characteristics. This review provides perspectives and guidance on the future directions of valley‐straintronics and flexible 2D optoelectronics using TMDs, highlighting the substantial promise of valley‐strain engineering in TMDs for fundamental valley physics studies as well as practical device applications. [ABSTRACT FROM AUTHOR]

Successful preparation of PVA/SrTiO3/CNT polymer nanocomposite films was accomplished via the solution casting method. The structural, optical, and thermal properties of the films were tested by XRD, SEM, FTIR, TGA, and UV-visible spectroscopy. Inclusion of the SrTiO3/CNT nanofillers with a maximum of 1 wt% drastically improved the optical and thermal properties of PVA films. SrTiO3 has a cubic crystal structure, and its average crystal size was found to be 28.75 nm. SEM images showed uniform distribution in the sample with 0.3 wt% of SrTiO3/CNTs in the PVA film, while some agglomerations appeared in the samples of higher SrTiO3/CNT content, i.e., at 0.7 and 1.0 wt%, in the PVA polymer films. The inclusion of SrTiO3/CNTs improved the thermal stability of PVA polymer films. The direct and indirect optical band gaps of the PVA films decreased when increasing the mass of the SrTiO3/CNTs, while the single-oscillator energy (E0) and dispersion energy (Ed) increased. The films' refractive indices were gradually increased upon increasing the nanofillers' weight. In addition, improvements in the optical susceptibility and nonlinear refractive indices' values were also obtained. These films are qualified for optoelectronic applications due to their distinct optical and thermal properties. [ABSTRACT FROM AUTHOR]

The structural, optoelectronics, and transport properties of TlTaO3 compounds were determined utilizing the full potential augmented plane wave approach using first‐principle method. We have considered the generalized gradient approximation for structural optimization and modified Becke–Johnson for electronic properties. The electronic properties reveal that the studied TlTaO3 possesses direct bandgap of magnitude 1.52 eV. Between 0 and 12 eV, optical spectra calculations are made, taking into account the real and imaginary parts of the dielectric function, refractive index, and loss function. The transport properties are estimated considering Boltzmann transport theory. The Seebeck coefficient, electrical conductivity, thermal conductivity, and power factor are all assessed using the Boltzmann transport theory. The optimized thermoelectric response of the examined TlTaO3 is produced by the improved carrier mobility, which also improves the thermoelectric efficiency of the TlTaO3. The obtained results will act as a theoretical road map for upcoming experimental and commercial TlTaO3 applications. [ABSTRACT FROM AUTHOR]

In this work, we delve into the investigation of the structural, electronic, and optical properties of Ba2NbBiS6 and Ba2TaSbS6 chalcogenide-based double perovskites, which are structured in the cubic space group Fm3̄m form. We have performed first-principles calculations using density functional theory (DFT) to study the above properties. The electronic band structure and density of states of this compound have been investigated, and their results show that Ba2NbBiS6 and Ba2TaSbS6 exhibit a semiconducting nature with an indirect energy gap of 1.680eV and 1.529eV, respectively. Furthermore, an investigation was conducted on the optical properties of the compounds throughout the energy range spanning from 0eV to 55eV. This investigation focused on many parameters, including dielectric functions, optical reflectivity, refractive index, extinction coefficient, optical conductivity, and electron energy loss. The optical data obtained from the calculations reveals that all compounds demonstrate isotropy in optical polarization. Furthermore, it has been noted that our compounds exhibit absorption properties inside the ultraviolet (UV) region. Consequently, these materials hold promise as potential candidates for various applications, such as UV photodetectors, UV light emitters, and power electronics. This is primarily attributed to their inherent absorption limits and the presence of prominent absorption peaks in this spectral range. In brief, chemical mutation techniques have been employed to manipulate the characteristics of double-sulfide perovskites to develop durable and environmentally friendly perovskite materials suitable for solar purposes. [ABSTRACT FROM AUTHOR]

Investigating interface engineering by piezoelectric, flexoelectric and ferroelectric polarizations in semiconductor devices is important for their applications in electronics, optoelectronics, catalysis and many more. The interface engineering by polarizations strongly depends on the property of interface barrier. However, the fixed value and uncontrollability of interface barrier once it is constructed limit the performance and application scenarios of interface engineering by polarizations. Here, we report a strategy of tuning piezotronic effect (interface barrier and transport controlled by piezoelectric polarization) reversibly and accurately by electric pulse. Our results show that for Ag/HfO2/n-ZnO piezotronic tunneling junction, the interface barrier height can be reversibly tuned as high as 168.11 meV by electric pulse, and the strain (0–1.34‰) modulated current range by piezotronic effect can be switched from 0–18 nA to 44–72 nA. Moreover, piezotronic modification on interface barrier tuned by electric pulse can be up to 148.81 meV under a strain of 1.34‰, which can totally switch the piezotronic performance of the electronics. This study provides opportunities to achieve reversible control of piezotronics, and extend them to a wider range of scenarios and be better suitable for micro/nano-electromechanical systems. Interface engineering by local polarization is becoming increasingly important for tunable electronics. Here, authors demonstrate an electric pulse-tuned piezotronic effect in Ag/HfO2/n-ZnO junction, enabling reversible and accurate regulation of barrier height and piezotronic modification range. [ABSTRACT FROM AUTHOR]

This contribution reports extensive studies on structure–property correlations of two isoelectronic betaine metamers (positional isomers). These zwitterions differ from each other with respect to bonding modes of pyridinium acceptors (Reichardt's mode: through N‐atom versus Brooker's mode: through C‐atom) with the p‐phenylene bridged phenolate donors. Various quantum chemical methodologies are used in this investigation, with time‐dependent (TD) and coupled perturbed (CPHF) theories for computations of many molecular response properties. Analysis of first hyperpolarizabilities (β) indicates that Reichardt's metamer (ωB97xD: β = 349.5 × 10−30 esu) is more efficient chromophore (~5‐fold enhanced) than Brooker's metamer (ωB97xD: β = 69.4 × 10−30 esu). The gyratory abilities of the bridge junctions resulted in a cohort of metastable conformations, in the rotational potential energy surfaces (PES) of the two metamers. Moreover, rotational PES establishes that intermediary torsions are suitable for optimal chromophore design strategies (Reichardt's metamer: β = 956.5 × 10−30 esu, and Brooker's metamer: β = 1104.7 × 10−30 esu), Thus suitable conformational manipulations, can be used to obtain more efficient zwitterionic molecular chromophores. Compared unbridged prototype molecules, p‐phenylene bridged zwitterions showed ~6–9 times enhanced values of β. In addition, important aspects of suitable chromophore design strategies are suggested. [ABSTRACT FROM AUTHOR]

This study investigates the alterations in structural, electronic, and optical characteristics of ZnSe1−x Inx (x = 0%, 12.5%, 25%) employing the framework of density functional theory (DFT), utilizing generalized gradient approximation (GGA) in conjunction with the full‐potential linearized augmented plane wave (FP‐LAPW) approach. The findings reveal that pure ZnSe exhibits a direct bandgap of 1.79 eV at the Γ point, which reduces to 0 eV upon doping with Indium, indicating a transition to metallic characteristics. This change is attributed to the predominant involvement of the d‐orbital of Zn, s‐orbital of Se, and p‐orbitals of Indium in the valence band of ZnSe1−x Inx materials. Conversely, the s‐orbital of Zn predominantly contributes to the conduction band of undoped ZnSe, whereas the d‐orbitals of Indium play a significant role in the conduction band of ZnSe1−x Inx (x = 0%, 12.5%, 25%). Moreover, the study computes other optical parameters, including reflectivity, electron energy loss spectrum, extinction coefficient, refractive index, and absorption coefficient, as functions of photon energy. A notable observation is the considerable rise in the zero‐frequency dielectric constant, ε1(0), which increases from 5.0 in pure ZnSe to 40.0 and 50.0 in Indium‐doped ZnSe, highlighting a significant alteration in electronic properties. Furthermore, optical analyses demonstrate an expansion in the absorption coefficient spectrum, which extends from photon energies of 2.0 eV in pristine ZnSe to begin at 0 eV in Indium‐doped variants, indicating a broadening of the material's capacity to absorb light across a wider spectrum of photon energies. This expansion infers improved light absorption potential, which could be particularly beneficial for the fabrication of light‐emitting modules and solar energy converters. These insights underline the considerable influence that Indium incorporation exerts on the band architecture and optical responses of ZnSe, offering critical directions for the advancement of optoelectronic devices. [ABSTRACT FROM AUTHOR]

The development of two-dimensional (2D) materials has received wide attention as a generation of optoelectronics, thermoelectric, and other applications. In this study, a novel 2D material, PbN, is proposed as an elemental method using the prototype of a recent reported nitride (J. Phys. Chem. C 2023, 127, 43, 21,006-21014). Based on first-principle calculations, the PbN monolayer is investigated as stable at 900 K, and the isotropic mechanical behavior is addressed by the Young's modulus and Poisson's ratio at 67.4 N m-1 and 0.15, respectively. The PbN monolayer also presents excellent catalytic performance with Gibbs free energy of 0.41 eV. Zero bandgap is found for the PbN monolayer, and it can be opened at about 0.128 eV by forming a heterostructure with CdO. Furthermore, the PbN/CdO is constructed by Van der Waals interaction, while the apparent potential drop and charge transfer are investigated at the interface. The PbN/CdO heterostructure also possesses excellent light absorption properties. The results provide theoretical guidance for the design of layered functional materials. [ABSTRACT FROM AUTHOR]

In this investigation, the sol-gel spin coating technique was utilized to fabricate ZnO and ZnO films doped with Iridium (Ir) onto p-Si substrates. The objective was to analyze their optical and morphological characteristics and assess their potential for heterojunction applications. Morphological inspection and optical evaluation were carried out by Atomic Force Microscopy (AFM) and Ultraviolet-visible (UV-VIS) studies, respectively. With the incorporation of Ir, the optical band gap of ZnO films reduced from 3.21 eV to 3.08 eV. Analysis of AFM images revealed that Ir substitution led to a reduction in the roughness of the surface of the fabricated films. The optoelectrical features of the heterojunction structures were examined under varying illumination levels and in dark conditions. Upon evaluating the optoelectrical characteristics of the produced diodes, it was observed that the ideality factor (n) and the barrier height (OB) declined, while series resistance (fls) increased with the introduction of Ir. These findings emphasize that the inclusion of Ir into the ZnO structure has a discernible impact on optical parameters. [ABSTRACT FROM AUTHOR]

The main aim of this article is to analyse the Si solar cell's behaviour when it is exposed to light of different colours. An experimental work, with 100 experimental tests, was carried out, using an RGB LED. In order to obtain better fitting of the characteristic curves' results, we used a novel discrete model, d1MxP. The obtained results showed that all experimental points of the tests were inside the two triangles that connected the three theoretical primary colours and the three experimental primary colours in the chromaticity diagram. With this diagram, the colour purity could be determined, which presented values between 20% and 60%. The primary colours of the three different LEDs of the light source presented a dominant wavelength that corresponded to the peak wavelengths of the light source spectrum, which showed high purity. However, the obtained results show that mixing colours may not lead to an increase in the cell's output power. Additionally, an increase in the cell's temperature was observed, due to the surplus absorbed energy, which was converted into heat, being one of the causes of the cell's efficiency reduction. [ABSTRACT FROM AUTHOR]

Single‐molecule optoelectronics offers opportunities for advancing integrated photonics and electronics, which also serves as a tool to elucidate the underlying mechanism of light‐matter interaction. Plasmonics, which plays pivotal role in the interaction of photons and matter, have became an emerging area. A comprehensive understanding of the plasmonic excitation and modulation mechanisms within single‐molecule junctions (SMJs) lays the foundation for optoelectronic devices. Consequently, this review primarily concentrates on illuminating the fundamental principles of plasmonics within SMJs, delving into their research methods and modulation factors of plasmon‐exciton. Moreover, we underscore the interaction phenomena within SMJs, including the enhancement of molecular fluorescence by plasmonics, Fano resonance and Rabi splitting caused by the interaction of plasmon‐exciton. Finally, by emphasizing the potential applications of plasmonics within SMJs, such as their roles in optical tweezers, single‐photon sources, super‐resolution imaging, and chemical reactions, we elucidate the future prospects and current challenges in this domain. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) materials are widely used in numerous optoelectronic devices due to their ultra‐thin dimensions and versatile surfaces. However, less attention is paid to distinguishing the light‐matter interactions along the vertical and horizontal paths within the same 2D lattice, as well as comparatively investigating the optoelectronic behaviors between the sensitive top and bottom surfaces. Here, a dual‐crossbar configured architecture is designed and constructed based on Bi2O2Se semiconductor, featuring highly compact three‐in‐one assembly, namely bottom surface horizontal (BSH), middle sandwich vertical (MSV) and top surface horizontal (TSH) devices. The MSV with nanoscale channel possesses efficient separation and transportation of the photogenerated electrons and holes, responding faster to the light stimulation and compared favorably to the BSH and TSH devices. The optoelectric behaviors of the BSH device can be regulated by the characteristics of the substrate due to closer contact. Nevertheless, the performance of the TSH device is more sensitive to the environment, such as dopant absorption and heat dispersion, thus enabling the non‐volatile photoresponse and can be employed as an artificial optoelectronic synapse. This work highlights the importance of designing the device architecture based on the intrinsic structural advantages of 2D materials, paving the way toward integrated optoelectronics. [ABSTRACT FROM AUTHOR]

The current study reports on the shape, size distribution, structure, magnetic properties, and biocompatibility of potassium ferrite nanoparticles (KFeO2 NPs), which were produced using the traditional sol–gel method. The development of spherical nanoparticles with an orthorhombic structure has been verified using X-ray diffraction and Field emission scanning electron microscopy. According to transmission electron microscopy, the particles have a size of about 30 nm. The production of metal (Fe, K) bonds was demonstrated by thermogravimetric analysis and Fourier transform-infrared spectroscopy. The optical analysis shows that the KFeO2 nanoparticles' bandgap is 1.88 eV, which is within the visible spectrum. Further Photoluminescent properties were investigated and showed strong luminescence in 600 nm range thus confirming oxygen deficient property. The synthesized KFeO2 NPs exhibited superparamagnetic behavior, with a saturation magnetization of 22.12 emu/g, according to the vibrating sample magnetometer examination. Furthermore, as determined by MTT and BrdU assays, the observed in vitro cytotoxicity and lymphoproliferative effects appeared to be biocompatible and concentration-dependent. The MTT assay was used in an in vitro cytotoxicity test which demonstrated the biocompatibility of KFeO2 NPs at 100 mg/mL of particle concentration. The findings of the current study suggest that potassium ferrite magnetic nanomaterials, which have better optical qualities and less coercivity in optoelectronic instruments, could be used in transformer cores. They can also be used as iron-oxide-based nanomaterials for applications in the health and medical science sectors. [ABSTRACT FROM AUTHOR]

The current work aims to explore the structural and optical properties of Cu1−xNixO/ZnO nanostructured heterojunctions for optoelectronic applications. ZnO nanostructures and different Cu1−xNixO/ZnO (x; 0, 0.05, 0.10, 0.15 and 0.20) nanostructured heterojunctions were prepared by spray pyrolysis procedure on glass substrates. The surfaces morphology of the samples was examined by a scanning electron microscope (SEM). The energy dispersive X-ray (EDX) microscope was utilized to examine the elemental analysis. The XRD measurements show that ZnO nanostructures possess a hexagonal wurtzite structure, while Cu1−xNixO nanostructures possess monoclinic structures. The FT-IR spectroscopy was performed to explore the chemical bondings and functional groups. The UV–visible-NIR spectrophotometer was used to investigate the optical properties. The optical constants (refractive index, extinction coefficient, dielectric constants, optical conductivity) of the prepared samples have been investigated. The first-order linear optical susceptibility, third-order optical susceptibility and nonlinear refractive index are also studied. The obtained results show that the optical parameters of Cu1−xNixO/ZnO heterojunction could be tuned through controlling the Ni content. These novel findings nominate Cu1−xNixO/ZnO nanostructured heterojunctions for a plenty of optical, photocatalytic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

Context: The 2D AlN/BN planer heterostructure is a promising wide band gap semiconductor, but systematic studies of its bandgap and optical characteristics under applied strain are scarce. Here, the engineering property of 2D AlN/BN comprising bandgap nature transition and optical absorption capability (from unstrained to strained) have been investigated using density functional theory calculations. The formation energy calculations confirm the stability of the simulated nanoheterostructure. The electronic band structure calculations demonstrate that nanoheterostructure is an indirect bandgap material with a large bandgap of 5.26 eV, which can be modified effectively by applying strain. According to the calculations, the transition from indirect to direct band gap behavior has been observed at +15% biaxial strain with 2.71 eV band gap energy. Meanwhile, calculations for optical absorption and dielectric function reveal that the system has significant absorption peaks in the ultraviolet region which are very sensitive to applied strain. As strain increases, the first absorption peaks are shifted towards a lower energy range from 5.73 eV (Ꜫ= 0 %) to 3.76 eV (Ꜫ = +15%), which features an enhancement of optical absorption for solar and solar-blind regions. Furthermore, we determined that the band edge positions in 2D AlN/BN straddled the water redox potential under strain, indicating its effectiveness as a proficient photocatalyst. These characteristics make 2D AlN/BN planer nanoheterostructure a promising candidate for applications in optoelectronics and photocatalytic water splitting performance. Methods: First principles computations based on density functional theory were employed to carry out all the calculations with a self-consistent approach. For solving the Kohn-Sham equations, the first principles dependent full-potential linearized augmented plane wave scheme were adopted. For addressing the exchange-correlation effects, the generalized gradient approximation of PBEsol functional was used. To prevent interaction between the periodic images, we have inserted a vacuum region of 10 Å in the z-direction. Non-negligible weak dispersion corrections in nanoheterostructure were considered by using the DFT-D3 method of Grimme's. The locally modified Becke-Johnson (lmBJ) exchange potential has also been applied to compute electronic and optical properties in this research to obtain more accurate information. [ABSTRACT FROM AUTHOR]

All-inorganic perovskites have garnered significant attention in optoelectronics. Herein, square CsPb2Br5 nanosheets, with lateral dimensions of up to 200 μm and a thickness of less than 50 nm, were successfully synthesized via a straightforward aqueous method using HBr as a morphology-tailoring agent. A photodetector composed of a single nanosheet was subsequently fabricated and exhibited remarkable photodetection capabilities, demonstrating a detectivity of 5.98 × 109 Jones. These findings offer new perspectives on the synthesis and utilization of CsPb2Br5 and other perovskite nanostructures in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Recent optoelectronics domain studies concluded the increased need to provide improved, stable, and efficient designs to operate high-power NIR (Near-infrared) laser diodes. The existing current regulators provide either stability or high efficiency, with the actual studied design representing a solution providing both advantages in a complex constant current driver. Therefore, this study covers the LTI (Linear Time-Invariant) analysis of a cascade feedback loop current regulator, aiming to achieve a constant current through a high transconductance load. Furthermore, this analysis also refers to such transconductance loads as NIR laser diode bars, having their emission spectrum closely matching one major absorption band of Nd:YAG (Neodymium-dopped Yttrium Aluminum Garnet) solid-state lasers, potentially providing an increased-stability solution to high power, continuous wave side-pumped applications, as well as various DPSS (Diode-Pumped Solid-State) laser prototypes. This design is a suitable solution for an infinite transconductance load, allowing the indefinite power increase in either direct diode or pumped laser applications while maintaining adequate stability. However, as it will be covered, multiple constraints occur for this hardware design. [ABSTRACT FROM AUTHOR]

Chalcogenide composites, a category of non-oxide glasses, have shown great potential in various applications such as optoelectronics, thermal imaging, memory-switching devices, lasers, and more. Owing to the distinctive physical properties inherent in chalcogenide glasses, these materials have garnered significant interest across various technological domains. This study aims to analyze the impact of incorporating sulfur (S) and antimony (Sb) into (S3Sb2)x(S2Ge)100−x:x = 10, 20, 30 chalcogenide composites, assessing their radiation shielding, structural, physical, and electrical properties. Three distinct composites, designated as SSbGe-10, SSbGe-20, and SSbGe-30, are irradiated with gamma photons across an energy range of 0 to 15 MeV. The assessment of the radiation shielding attributes is conducted through the utilization of the FLUKA Monte Carlo (MC) Code. Phillips and Thorpe's theory is employed to analytically estimate structural and physical attributes such as Coordination Number (CN), bond-bending constraints (NS), bond-stretching constraints (NC), constraints Number (Ncons), Floppy mode (F), and stoichiometry (R). The electrical features of the provided specimens are analyzed through the utilization of the effective electron conductivity (Ceff), as ascertained by the Phy-X: PSD software. The findings indicate that the augmentation of the x value within the range of 10–30 wt.% positively augments the gamma photon shielding efficacy of the composite materials. Both NS and NC demonstrate diminishing patterns, encompassing the range of 2.64 to 2.575 and 7.56 to 7.30, respectively. Additionally, the stoichiometry (R > 1) for the investigated samples indicates that the chosen glasses are rich chalcogenide composites. The exhaustive examination of the physical, radiation shielding, and electrical characteristics of the prepared chalcogenide glasses provides valuable insights for subsequent investigations into various chalcogenide glass formulations. [ABSTRACT FROM AUTHOR]

Herein, a lead-free double perovskite is synthesized utilizing an antisolvent recrystallization technique. The double perovskite Na 2 AgBiBr 6 is studied in detail, including its crystal structure, stability, morphology, electronic, optical, and thermoelectric properties. X-ray diffraction (XRD) confirms the formation of Na 2 AgBiBr 6 double perovskite and demonstrates remarkable structural stability. Crystals of uniform multifaceted Na 2 AgBiBr 6 are seen by scanning electron microscopy (SEM). Polycrystalline-Na 2 AgBiBr 6 crystals in a cubic ordered phase by the solution synthesis approach are ensured by TEM and electron diffraction analysis. Furthermore, energy-dispersive X-ray spectroscopy (EDX) mapping indicates the overlapping of Na, Ag, Bi, and Br elements and the uniform content of each element in the synthesized material. According to UV–vis spectroscopy, a band gap of 2.6 eV is observed. Further, the density functional theory (DFT) calculations suggested the structural as well as thermal stability acquired by tolerance factor and negative formation energy, respectively. DFT-predicted lattice parameter and band gap are verified by XRD and UV–vis spectroscopy, respectively. Elastic properties confirmed the mechanical stability, anisotropy, and ductile nature. The optical properties revealed the higher absorbance and low reflectivity in the energy range 0–6 eV. The thermoelectric attributes ensure the higher electrical conductivity and low thermal conductivity resulting in a figure of merit (ZT) value of 0.77. The outcomes of this research propose that the lead-free and eco-friendly Na 2 AgBiBr 6 double perovskite holds considerable potential as absorber layer material for solar cells and for thermoelectric device applications. [ABSTRACT FROM AUTHOR]

The remarkable optoelectronic features of halide perovskite promote their potential applications in semiconductor devices beyond solar cells, which require high-quality single crystals with controlled defect levels. Herein, we investigated the synthesis mechanism of chemical vapor deposited single-crystalline all-inorganic perovskite microplates (MPs), and reported a defect-modulated photocurrent which is closely related to the growth sequence of the MPs. The MP synthesis initiates from island-like nano-disks, and subsequently transits to a layer-by-layer fashion, resulting in a defect-rich area at the center of the MPs. At elevated temperatures, these central defects may be thermally activated and become highly mobile, leading to photoluminescence quenching and degression of local and overall optoelectronic attributes, as evidenced by the spatial resolved optical and electrical scanning probe microscopy. Overall, this work shines light on the formation, proliferation and dynamics of defects in perovskites, and offers guidance for preparation of high-quality perovskites micro-crystals for functional semiconductor devices with high temperature stability. [ABSTRACT FROM AUTHOR]

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Transparent photovoltaics (TPVs) generate electric power by selectively harvesting ultraviolet and/or near‐infrared light. If integrated with electronic products, TPV can sustainably power the products without affecting the user experience. Future electronics require flexibility and lightweight, hence the integrated TPV should also be flexible. To achieve this, a flexible, transparent conducting platform is desirable. A binary transparent conductor (TC) based on Ag(O) has been studied for flexible TPV. The oxygen‐induced Ag growth provides better Ag wettability, enabling a low sheet resistance of 12.5 Ω sq−1 at an Ag thickness of 6.5 nm. The AZO/Ag(O) binary structure, with an average visible transmittance value of 86%, has a figure of merit of 17.7 (10−3 Ω−1), which surpasses conventional TCs such as fluorine‐doped tin oxide and indium‐doped tin oxide. Furthermore, the multilayer design of Ag(O)‐based TC allows interfacial engineering to enhance the performance of TPV. The optimum photovoltaic performance of NiO/ZnO TPV is achieved with an AZO thickness of 12 nm, providing a performance enhancement of 700%. The NiO/ZnO/AZO/Ag(O) device exhibits a stable photovoltaic effect with a consistent open‐circuit voltage value of 0.4 V after numerous bending cycles with a bending radius of 0.7 cm. [ABSTRACT FROM AUTHOR]

We examine the electronic, optical, and dielectric properties of Cu-, Ag-, and Au-doped and undoped cadmium hydroxide [Cd(OH)2)] using first-principles density functional theory. The electronic investigations show the semiconducting characteristics of Cd(OH)2 with a band gap of about 1.83 eV. These properties were investigated along two mutually perpendicular directions of light polarization and as a function of the incident light energy (photon energy). The frequency-dependent dielectric function is obtained from the electronic structure calculations. The optical quantities, such as absorption, transmission, refractive index, etc., are also calculated to investigate the optical behavior. The metal doping (Cu, Ag, and Au) significantly affects the properties of Cd(OH)2 in the infrared and low-energy visible regions of the electromagnetic spectrum. For photon energies greater than 4.0 eV, the effect of these doping elements on the optical and dielectric properties is negligible. These materials exhibit negative dielectric permittivity, which is one of the fundamental features of a photonic crystal. The low-energy absorption spectrum of the doped material shows a shift towards the longer wavelengths compared to the undoped Cd(OH)2. This shift is maximum (minimum) for Cu (Au)-doped Cd(OH)2, whereas Ag-doped Cd(OH)2 has an intermediate shift compared to Cu- and Au-doped Cd(OH)2. This relative shift may be attributed to their atomic radii. These are good candidates for the absorption of UV radiation. The calculated static refractive index of Ag-doped Cd(OH)2 is comparable to SiO2. These electronic and optical investigations reveal that the considered materials are excellent candidates for optoelectronic device applications. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis, analysis, and utility of films comprising deep eutectic solvent (DES) grafted activated charcoal (AC) within a polyvinyl alcohol (PVA) matrix for optoelectronic device applications. The fabrication process involves the dispersion of DES functionalization AC into the PVA solution, followed by casting onto substrates with controlled drying. Comprehensive characterization encompassing X‐ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis spectroscopy, Fourier‐transform infrared spectroscopy (FTIR), and impedance spectroscopy which discerns the films microstructure, morphology, conductance, band‐gap, and optical traits. The DES grafted AC infusion with variable concentration has significantly influenced optical absorbance and reduced the band gap indicating efficient charge mobility. Furthermore, the impedance analysis has revealed the electrical conduction of the film to be 1.8 × 10−6 Ω−1 m−1. In summary, the dispersion of DES modified AC in the PVA matrix have converted the insulating PVA to a semiconducting polymeric film with reduced band‐gap and increased absorption, which present a propitious avenue for wide array of optoelectronic devices, such as thin film transistors, photovoltaics, LEDs, photodetectors, and many such applications. [ABSTRACT FROM AUTHOR]

This research discusses incorporating a single magnesium porphyrin molecule into a semiconducting single‐walled carbon nanotube (SWCNT) for solar cell applications. Using density functional theory (DFT), the study examines the optical and electronic properties of the isolated magnesium porphyrin molecule and two configurations of the hybrid system. Results show structural stability due to charge transfer between the molecule and the nanotube. Different exchange‐correlation functionals (GGA and HSE06) yield varied bandgap results, affecting light absorption. Integration of the molecule into the SWCNT reduces the bandgap. Encapsulation of the molecule influences absorption and stability under irradiation. These encapsulated systems exhibit type II heterojunction characteristics, making them promising for organic solar cells based on SWCNTs, offering potential for highly efficient solar cells. [ABSTRACT FROM AUTHOR]

Ultra-flexible and stretchable organic photodetectors (s-OPDs) sensitive in the near-infrared (NIR) region hold great potential for wearable health monitoring with excellent physiological signal and skin conformability. However, the development of OPDs that combines NIR sensitivity, low power consumption, low cost, simple fabrication structure, and good mechanical properties is still challenging and has not been well explored. In this work, we report a self-powered s-OPD with a simple fabrication structure used for organic solar cells and a detectivity of more than 1 × 1012 Jones (corrected by noise current) in the NIR region at 10% tensile strain and short response time (2.46 μs), representing state-of-the-art performances. Reducing energetic disorders other than discrete traps in photoactive layers is more crucial to further reduce the dark current at zero bias. The dark current of the OPDs exhibits higher mechanical stability than photocurrent due to the slower degradation of the parallel resistance than the series resistance under tensile strain. The higher stability of dark current enables the s-OPDs as a stretchable organic photoplethysmogram heart rate sensor, showing excellent detectivity under 30% strain or 800 stretching–release cycles at 10% strain, indicating the great potential for application in wearable optoelectronics. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) self‐powered photodetectors have attracted considerable attention due to their exceptional sensitivity, and low dark current. However, the poor responsivity of single heterojunctions with type‐III band alignment is primarily attributed to band‐to‐band tunneling. The implementation of a double heterojunction has the potential to enhance photovoltaic responsivity, enable broadband detection, and improve response speed. In this study, a back‐to‐back type‐III band alignment based on SnSe2/Bi2Se3/MoTe2 double heterostructure by dry transfer method is designed. As a result, it exhibited an impressive photovoltaic performance in the overlapping region. Achieving a maximum responsivity (R), external quantum efficiency (EQE), photoelectric conversion efficiency (PCE), and specific detectiviy (D*) of 493 mA W−1, 76 %, 3 % and 1.8 × 1011 Jones at a gate voltage (Vg) of 60 V under 808 nm illumination. It can be ascribed to the effective depletion region at the SnSe2/Bi2Se3 interface and the reversed band edge from depletion to accumulation mode at Bi2Se3/MoTe2 interface. In addition, a faster response speed of 553/583 µs and a lower dark current of 2.9 pA can be obtained. Moreover, this double heterostructure achieves better photovoltaic performance with Vg compared to the single MoTe2/SnSe2 heterojunction. These results demonstrates the potential as a candidate for back‐to‐back type‐III band alignment in low power optoelectronics. [ABSTRACT FROM AUTHOR]

This study investigates into the synthesis, characterization, and multifaceted analysis of a composite material comprised of copper vanadium oxide (CVO) and graphitic Carbon Nitride g-C 3 N 4 (GCN). The fabrication of the composite was achieved through wet-chemical method followed by annealing at 600 °C for 3 h, ensuring controlled composition and structure. The characterization process encompassed X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–visible spectroscopy, unveiling the composite's crystalline structure, novel nano-rod morphology with decorated flakes, and UV–visible light activation capability. The obtained band gap of approximately 2.7 eV signified the composite's optical properties. Electrochemical analysis, including cyclic voltammetry (CV), highlighted the composite's robust biosensing attributes, particularly in response to ascorbic acid. The conducting and metallic characteristics of the composite enhanced its reactivity, promising applications in biosensors and energy storage devices. This comprehensive investigation elucidates the multifaceted potential of the CVO/GCN nano-composite across diverse optoelectronic realms. [ABSTRACT FROM AUTHOR]

A synthesis and characterization of luminescent nano‐heterostructures consisting of CdSe nanorod (NR) cores and a ZnO shell with up to three monolayers of ZnO is reported. The core/shell heterostructures show a tunable, dual photoluminescence (PL) in visible and Near Infrared (NIR) spectral ranges. Upon shelling the visible PL band attributed to the carrier recombination within the CdSe core shifts to lower energy by ≈0.05 to 0.15 eV relative to the bare CdSe NRs, due to a reduced quantum confinement. A NIR band, observed ≈0.4 – 0.5 eV below the PL energy of the CdSe core, is attributed to a type‐II carrier recombination across the CdSe/ZnO interface. The total PL quantum yield (PLQY) in the brightest heterostructures reaches ≈20%, increasing ≈100‐fold over the PLQY of the corresponding bare CdSe NRs. The average lifetimes of the visible PL in some heterostructures exceeds 100 ns, compared to ≈5 ns lifetime typical for bare CdSe NRs. The average PL lifetimes attributed to the type‐II charge separated states exceed one microsecond. Strong NIR PL, tunable in the 800–900 nm spectral range and the long‐lived charge separated state make the CdSe/ZnO core‐shell NRs appealing materials for exploitation in applications such as bioimaging, photocatalysis and optoelectronics. [ABSTRACT FROM AUTHOR]

Solid‐state hybrid materials with designability in topology and tunable photo‐responsiveness hold great promise for multitudinous applications from optoelectronics to information storage/communication. However, the judicious design and synthesis of metal–organic frameworks (MOFs) with intrinsically custom‐made nonlinear optical (NLO) properties including multiple photon absorption and harmonic generation effects suitable for miniaturized devices remain highly challenging. Herein, the design and synthesis of a novel pillared framework named after Zn‐TCPE‐DPNI MOF coordinated by zinc ions (Zn2+), aggregation induced emission (AIE) featured [1,1′‐biphenyl]‐4‐carboxylic acid (H4TCPE), and N,N′‐di(4‐pyridyl)‐1,4,5,8‐naphthalenetetracarboxydiimide (DPNI) are reported. The highly ordered Zn‐TCPE‐DPNI MOF single crystal exhibits tunable NLO responses by switching incident excitation wavelengths of a femtosecond laser from 900 to 1500 nm. The noticeable transformation from two‐ or three‐photon excited photoluminescence (2PL or 3PL) to the concurrent occurrence of 3PL and third harmonic generation (THG), and eventually to the mere emergence of THG with a high effective susceptibility χ(3) (3ω) of 2.9 × 10−12 esu is observed. This study paves a novel avenue for the design and synthesis of photoluminescent MOF crystals with tunable NLO responses toward the fabrication of multifunctional NLO devices targeted for optoelectronics and information communication. [ABSTRACT FROM AUTHOR]

Emerging nano-kirigami/origami technology enables the flexible transformations of 2D planar patterns into exquisite 3D structures in situ and has aroused great interest in the areas of nanophotonics and optoelectronics. This paper briefly reviews some milestone research and breakthrough progresses in nano-kirigami/origami from the aspects of stimuli approaches and application directions. Versatile stimuli for kirigami/origami, including capillary force, residual stress, mechanical force, and irradiation-induced stress, are introduced in the micro/nanoscale region. Appealing optical applications and reconfigurable schemes of nano-kirigami/origami structures are summarized, offering effective routes to realize tunable nanophotonic and optoelectronic devices. Future challenges and promising pathways are also envisioned, including design methods, innovative materials, multi-physics field driving, and reprogrammable devices. [ABSTRACT FROM AUTHOR]

In this paper, optical and transport properties of Polyvinyl Alcohol/Silver incorporated Zinc Oxide (PVA/Ag–ZnO) nanocomposites of varying Ag–ZnO nanoparticles content prepared by solution casting method are studied to explore their multifunctional applications. The nanocomposites are characterized using X-ray diffraction, Scanning electron microscope, Energy-dispersive X-ray analysis, UV–Visible spectroscopy and Fourier transform infra-red spectroscopy. The UV–visible spectra showed zero transmittance in the UV region with increasing Ag–ZnO nanoparticles content in the PVA matrix suggesting that the nanocomposites could be used as a potential UV shielding material. The optical band gap energy decreases from 5.77 to 1.54 eV with increasing Ag–ZnO nanoparticles content in the PVA matrix. Frequency- and temperature-dependent dielectric measurement of the samples reveals maximum dielectric constant at PVA/15 wt% Ag–ZnO nanocomposite. Dielectric loss results showed a lossless behaviour at higher frequencies (< 0.2), suggesting that the prepared samples are suitable for use in high-frequency applications. The AC conductivity studies reveal that electrical conduction mechanism in the nanocomposites is governed by the correlated barrier hopping mechanism. Activation energy calculation indicates the involvement of two different types of conduction mechanism in the samples. The Nyquist plot for all the samples is fitted using the equivalent circuit model. The studied results show that the PVA/Ag–ZnO nanocomposites can serve as potential candidates for optoelectronic and electronic device application. [ABSTRACT FROM AUTHOR]

The electronic, optoelectronic, linear and nonlinear optical (NLO) properties of some corannulenes of formula C5n2H5n (with n = [2,4]), doped with boron–nitride units at the rim position, have been studied using density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. This work aims to substitute B–N units at the rim position in some corannulene structures in order to propose new materials for electronic, optoelectronic and nonlinear optical applications. According to the investigations carried out, the analysis of the cohesive energies of the studied corannulene derivatives indicates that they are energetically stable materials. Based on the |HOMO–LUMO| energy gap values, we find that corannulenes doped with B–N units at the rim position exhibit the same semiconducting nature as the parent structure from which they derive. Moreover, the value of first-order hyperpolarizability (β0) of structures containing B–N isoelectronic units at the rim position in corannulenes is higher than that of the urea molecule considered as a reference molecule commonly used in nonlinear optics (NLO). We hope that the present work will also pave the way for the design of high-performance nonlinear optical materials based on boron–nitride-doped corannulene at the rim position. TD/B3LYP-D3/6–31 + G(d) calculations revealed that among the proposed derivatives, the compounds C35B5N5H15 and C70B5N5H20 exhibit high photo-current response in the visible range. This gives these new materials good performances for optoelectronic applications. Although all the studied properties of the doped structures with B–N units at the rim position are not better than those at the spoke position reported in the literature, these proposed systems have good capabilities to be used as suitable organic semiconductors in the photovoltaic field. [ABSTRACT FROM AUTHOR]

Recently, the emerging 2D materials MXene have gained a surge of attention to the production of optoelectronics devices such as solar cells, plasmonic, phototransistors, photodetectors, light‐emitting diodes, photothermal therapy, and so on. Its outstanding optical and electrical characteristics, unique structure, and large specific surface area make it suitable for future use in modern optoelectronics including ultrafast lasers, light emitters, modulators, and plasmonic generators. There is a lack of critical analysis on the prospects, challenges, overview of synthesis methods, mechanisms, and future research directions of MXene despite having some reviews have been published on the applications of MXene. Therefore, this study critically analyzed the existing challenges of MXene, such as poor stability in an oxygen environment, inadequate mechanical properties, ease of stacking, temperature barrier, and so on. In addition, the fundamentals, preparation techniques, properties, and applications of MXene have been summarized. The mechanism, limitations, and benefits of different preparation methods have been mentioned. A comprehensive analysis and guidelines have been provided to improve the existing synthesis methods. The ways to overcome these challenges, prospects, and future markets of the MXene‐based optoelectronic devices have been described. [ABSTRACT FROM AUTHOR]

In the current work the effect of amorphous silicon (a-Si) substrates on the structural, optical and electrical properties of zinc phthalocyanine (ZnPc) thin films is explored. ZnPc thin films are coated onto glass and a-Si substrates by the thermal evaporation technique under a vacuum pressure of 10–5 mbar. It is observed that a-Si substrates lead to a lattice expansion, increased strain, increased stacking faults percentages and increased defect densities. Coating ZnPc films onto a-Si substrates reduced the crystallite sizes from 28 to 24 nm and decreased the energy band gap from 3.20 eV to 2.50 eV. In addition the temperature dependent electrical resistivity measurements has shown that deeper acceptor levels are formed in the energy band gap of ZnPc. Although the room temperature electrical resistivity increased by 45.5% upon coating the films onto a-Si, the light absorption in ZnPc increased by more than 24 times at 2.65 eV. The enhanced light absorption together with the shift in the energy band gap indicates that a-Si makes ZnPc films more adequate for optoelectronic applications. [ABSTRACT FROM AUTHOR]

All-solution-processed organic optoelectronic devices can enable the large-scale manufacture of ultrathin wearable electronics with integrated diverse functions. However, the complex multilayer-stacking device structure of organic optoelectronics poses challenges for scalable production. Here, we establish all-solution processes to fabricate a wearable, self-powered photoplethysmogram (PPG) sensor. We achieve comparable performance and improved stability compared to complex reference devices with evaporated electrodes by using a trilayer device structure applicable to organic photovoltaics, photodetectors, and light-emitting diodes. The PPG sensor array based on all-solution-processed organic light-emitting diodes and photodetectors can be fabricated on a large-area ultrathin substrate to achieve long storage stability. We integrate it with a large-area, all-solution-processed organic solar module to realize a self-powered health monitoring system. We fabricate high-throughput wearable electronic devices with complex functions on large-area ultrathin substrates based on organic optoelectronics. Our findings can advance the high-throughput manufacture of ultrathin electronic devices integrating complex functions. [ABSTRACT FROM AUTHOR]