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Bandgap engineering of transition metal dichalcogenides (TMDCs) opens up opportunities to design broadband photodetectors via interlayer transition in type-II van der Waals (vdWs) heterostructures. However, the photoresponse related to interlayer coupling remains elusive, because of the limited efficiency of interlayer electron–hole generation and separation. Herein, we report the near-infrared optoelectronic response driven by the interlayer transition in MoSe2/WSe2 bilayer–bilayer vdWs heterostructure grown by one-pot chemical vapor deposition (CVD). It is found that the interlayer distance of the MoSe2 bilayer and WSe2 bilayer approximately reaches a single atomic layer, which enhances the strength of interlayer coupling. A substantial build-in potential in MoSe2/WSe2 heterostructure leads to rapid separation of photogenerated carriers. Moreover, this MoSe2/WSe2 bilayer–bilayer heterostructure exhibits high optoelectronic performance from the visible to near-infrared spectrum, obtaining a near-infrared photoresponse time of 38 μs at 940 nm. Our work may provoke further exploration of interlayer transition in type-II TMDCs heterostructures and their applications in broadband photodetectors. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive analysis of the structural, morphological, and electrochemical properties of the synthesized Ti₃C₂ and Ti₃C₂/Fe1‐xBaₓCr₂O₄ nanocomposite, highlighting their potential as electrode materials for supercapacitors. Utilizing X‐ray diffraction (XRD), we established the crystalline structure, revealing crystallite sizes of 13.29 nm and 20.00 nm for Ti₃C₂ and the nanocomposite, respectively, with corresponding crystallinity indices of 60% and 70%. Scanning electron microscopy (SEM) showed that Ti₃C₂ exhibited a characteristic layered structure, while the composite demonstrated a more granular morphology with integrated ferrite particles, enhancing its magnetic properties. Energy dispersive X‐ray spectroscopy (EDS) confirmed the elemental composition, including titanium, iron, barium, and chromium, validating the successful synthesis of the nanocomposite. Photoluminescence (PL) analysis indicated a significant band gap reduction from 2.05 eV for Ti₃C₂ to 1.77 eV for the composite, suggesting enhanced light absorption capabilities. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results demonstrated impressive electrochemical performance, with a maximum specific capacitance of 728.5 F/g in 1 M H₂SO₄. These findings collectively underscore the structural integrity, enhanced electrochemical properties, and multifunctional potential of the Ti₃C₂/Fe1‐xBaₓCr₂O₄ nanocomposite for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

The advent of two-dimensional (2D) materials and their capacity to form van der Waals (vdW) heterostructures has revolutionized numerous scientific fields, including electronics, optoelectronics, and energy storage. This paper presents a comprehensive investigation of bandgap engineering and band structure prediction in 2D vdW heterostructures utilizing density functional theory (DFT). By combining various 2D materials, such as graphene, hexagonal boron nitride (h-BN), transition metal dichalcogenides, and blue phosphorus, these heterostructures exhibit tailored properties that surpass those of individual components. Bandgap engineering represents an effective approach to addressing the limitations inherent in material properties, thereby providing enhanced functionalities for a range of applications, including transistors, photodetectors, and solar cells. Furthermore, this study discusses the current limitations and challenges associated with bandgap engineering in 2D heterostructures and highlights future prospects aimed at unlocking their full potential for advanced technological applications. [ABSTRACT FROM AUTHOR]

Continuously manipulating the resonant wavelength of lasing modes within a large spectral range is of great significance for expanding device functionality. Here, to synthesize a single CsPbClxBr3‐x perovskite microwire with the energy bandgap gradient spanning from 2.33 to 2.83 eV along the length direction defined as the axis by using the vapor‐phase anion exchange method is proposed. A high‐quality (≈103), wide range (≈60 nm), and continuously tunable single‐mode laser is achieved in as‐prepared perovskite microwire alloy, which provides both gain media and microresonator. Simultaneously, the exciton recombination dynamics and atomic‐scale interdiffusion mechanisms at different components are clarified through time‐resolved photoluminescence (PL) spectra and theoretical calculations. The vacancy defects have a significant impact on the interdiffusion of halogen anions, excitonic recombination lifetime, and fluorescence quantum efficiency. The work provides a new strategy for the construction of new‐type broadband tunable lasers and high‐precision microspectrometers. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis of heavy-metal-free AgInS2 quantum dots (QDs) using a facile successive ionic layer adsorption and reaction (SILAR) method, exploring their application in quantum dot-sensitized solar cells (QDSSCs). The AgInS2 QDs were grown on mesoporous TiO2 via a two-stage SILAR process at room temperature. The optimization of Ag-S SILAR cycles (n) was performed to determine the ideal conditions, while the In-S SILAR cycles were held constant at seven cycles. X-ray diffraction (XRD) pattern analysis revealed an orthorhombic crystalline structure of the synthesized AgInS2 QDs. Analysis of the optical spectra revealed a reduction in the optical energy bandgap (Eg,op) of AgInS2 QDs from 2.00 eV to 1.92 eV and further to 1.78 eV as the value of n increased from 1 to 3. Employing AgInS2 QDs, a polysulfide electrolyte, and a CuS counter electrode, liquid-junction semiconductor QDSSCs were fabricated. Optimal conditions were achieved at n = 2, resulting in outstanding power conversion efficiency (PCE) of 3.57% (Jsc = 8.56 mA/cm2, Voc = 0.64 V, FF = 65.2%). Under reduced light intensity (0.25 sun), the PCE increased to 5.26%. The external quantum efficiency (EQE) spectrum of the best cells spanned 400−700 nm, maintaining a nearly constant EQE value of ~ 65% within the 400−600 nm range. Remarkably, the PCE achieved surpassed previously reported liquid-junction AgInS2 QDSSCs. These findings highlight the facile production of heavy-metal-free AgInS2 QDs through a room-temperature SILAR method and the tunable optical properties of AgInS2 QDs by controlling Ag-S SILAR cycles, revealing their potential as an efficient solar absorber. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have aroused worldwide efforts for developing optoelectronic devices due to their unique optical properties and low‐cost simple fabrication process. In recent years, various perovskites‐based miniaturized optical devices have been actively investigated due to their record‐breaking efficiency in different fields, including environmental monitoring, remote sensing, biomedical imaging, and optical communications. In this review, a succinct and critical survey of recently discovered organic–inorganic perovskite photodetectors providing insights into their structural properties and key performance parameters is staged. First, key features of perovskites‐based photodetectors emphasizing their optoelectronic and electrical properties are introduced. Then, the polarization‐sensitive detection of metal halide perovskites using polarization‐selective optical structures is discussed. The bandgap engineering for tailoring the properties of perovskite photodetectors by changing the chemical composition and material structures is also highlighted in this report. Finally, a perspective on future opportunities and current challenges for designing perovskite‐based optoelectronic devices is presented. [ABSTRACT FROM AUTHOR]

Abstract Dynamic random-access memory (DRAM) has been scaled down to meet high-density, high-speed, and low-power memory requirements. However, conventional DRAM has limitations in achieving memory reliability, especially sufficient capacitance to distinguish memory states. While there have been attempts to enhance capacitor technology, these solutions increase manufacturing cost and complexity. Additionally, Silicon-based capacitorless memories have been reported, but they still suffer from serious difficulties regarding reliability and power consumption. Here, we propose a novel Schottky barrier memory (SBRAM), which is free of the complex capacitor structure and features a heterojunction based on bandgap engineering. SBRAM can be configured as vertical cross-point arrays, which enables high-density integration with a 4F2 footprint. In particular, the Schottky junction significantly reduces the reverse leakage current, preventing sneak current paths that cause leakage currents and readout errors during array operation. Moreover, the heterojunction physically divides the storage region into two regions, resulting in three distinct resistive states and inducing a gradual current slope to ensure sufficient holding margin. These states are determined by the holding voltage (V hold) applied to the programmed device. When the V hold is 1.1 V, the programmed state can be maintained with an exceptionally low current of 35.7 fA without a refresh operation.

Abstract We have proposed leaky integrate-and-fire (LIF) neuron having low-energy consumption and tunable functionality without external circuit components. Our LIF neuron has a simple configuration consisting of only three components: one bandgap-engineered resistive switching transistor (BE-RST), one capacitor, and one resistor. Here, the crucial point is that BE-RST with a silicon–germanium heterojunction possesses an amplified hysteric current switching with a low latch-up voltage due to improved hole storage capability and impact ionization coefficient. Therefore, the proposed neuron utilizing BE-RST requires an energy consumption of 0.36 pJ/spike, which is approximately six times lower than 2.08 pJ/spike of pure silicon-RST based neuron. In addition, the spiking properties can be tuned by modulating the leakage rate and threshold through gate bias, which contributes to energy-efficient sparse-activity and high learning accuracy. As a result, our proposed neuron can be a promising candidate for executing various spiking neural network applications.

The solid solution Ba 5 In 2– x Y x Al 2 ZrO 13 (0 ≤ х ≤0.50) with hexagonal structure (space group P 6 3 / mmc) was prepared by the solid-state reaction method. The effects of isovalent Y3+-substitution on the structure, hydration, bandgap and transport properties have been investigated. The introduction of yttrium was accompanied by lattice expansion, which led to an increase in the concentration of protons during hydration. The doping did not lead to a significant increase in oxygen-ion conductivity since there was no change in oxygen stoichiometry. At the same time, doping led to an increase in ionic transport numbers due to a decrease in hole conductivity. Proton conductivity contribution and the values of proton conductivity increase with the increase in yttrium concentration. The phases with yttrium content x > 0.2 were predominant proton conductors at the temperature below 600°С under wet air. [ABSTRACT FROM AUTHOR]

Dynamic random-access memory (DRAM) has been scaled down to meet high-density, high-speed, and low-power memory requirements. However, conventional DRAM has limitations in achieving memory reliability, especially sufficient capacitance to distinguish memory states. While there have been attempts to enhance capacitor technology, these solutions increase manufacturing cost and complexity. Additionally, Silicon-based capacitorless memories have been reported, but they still suffer from serious difficulties regarding reliability and power consumption. Here, we propose a novel Schottky barrier memory (SBRAM), which is free of the complex capacitor structure and features a heterojunction based on bandgap engineering. SBRAM can be configured as vertical cross-point arrays, which enables high-density integration with a 4F2 footprint. In particular, the Schottky junction significantly reduces the reverse leakage current, preventing sneak current paths that cause leakage currents and readout errors during array operation. Moreover, the heterojunction physically divides the storage region into two regions, resulting in three distinct resistive states and inducing a gradual current slope to ensure sufficient holding margin. These states are determined by the holding voltage (Vhold) applied to the programmed device. When the Vhold is 1.1 V, the programmed state can be maintained with an exceptionally low current of 35.7 fA without a refresh operation. [ABSTRACT FROM AUTHOR]

Specifically, biocatalyst coupled semiconductor photocatalysts have great potential towards the eco-friendly decomposition of toxic organic dyes that contaminate water bodies. This study reports the synthesis of vermiwash activated molybdenum doped tin oxide (Mo:SnO2) nanomaterial, for the photocatalytic degradation of a representative cationic dye - methylene blue (MB). The photocatalytic performance of the synthesized nanoparticles was evaluated using UV-visible (UV-vis) spectroscopy and the degrading efficiency of MB dye was quantified. The addition of vermiwash resulted in a marked improvement in the photocatalytic activity of Mo:SnO2 nanoparticles, with a degradation efficiency of 96% achieved after 75 min of irradiation. The nanoparticles were characterized using XRD, SEM-EDX, TEM, FTIR, XPS and UV-vis to confirm the crystal structure, morphology, functional groups, elemental analysis and bandgap energy by using Tauc's plot. The study demonstrates the potential of vermiwash as a green and efficient bio co-catalyst for improving the photocatalytic activity of Mo:SnO2 nanoparticles regarding the degradation of textile effluents. Thus, this study paves a way for new eco-friendly approach for the synthesis of cost-effective, biocatalyst coupled semiconductor photocatalyst. [ABSTRACT FROM AUTHOR]

Bulk tin‐based monochalcogenides are composed of earth‐abundant, low‐cost, and non‐toxic chemical elements, which possess high thermoelectric properties making them candidate for waste heat recovery applications. Bandgap engineering offers opportunity to customize the characteristics of semiconductors as desired applications in microelectronic, thermoelectric, and so on. The bandgap of tin‐based monochalcogenides is systematically regulated by the solid‐solution method. The thermal and optical properties of SnSe(1–x)Sx (0 ≤ x ≤ 1) single crystals, synthesized successfully by a home‐modified Bridgman method, have been systematically investigated. A variety of characterizations, including x‐ray diffraction, electron microscopy, Raman spectroscopy, absorbance spectroscopy, and thermal analyzer, are employed to confirm the precise tuning of the component. As the S compositions increased from 0 to 1, the unit cell parameter, interplanar spacing, and optical phonon frequency exhibited a linear change, aligning with the expected bandgap shifts and calculated results. Our work will promote the advancement of the SnSe and SnS materials in areas including thermoelectricity and photovoltaics. [ABSTRACT FROM AUTHOR]

Germanium (Ge) is one of the most promising material platforms to enable the realization of monolithically integrated laser on silicon because it is a group-IV material with a pseudo-direct-band structure that can be converted into direct-bandgap either through the application of tensile strain or via the tin (Sn) incorporation in Ge. The bandgap modification enhances the light emission efficiency of Ge, where lasing can also be observed if a suitable cavity preserving the strain can be realized. In fact, several different research groups have reported lasing from strained Ge and GeSn optical cavities, however they all report lasing at low temperatures and room-temperature lasing, which is the ultimate goal required for a fully integrated laser, has not been demonstrated yet. In this work, we design an on-chip germanium cavity that has all the ingredients combined to make the room-temperature lasing possible. The design includes a 4.6% uniaxially tensile strained Ge gain medium embedded in a Fabry-Perot like cavity composed of two distributed Bragg reflectors. 3-dimensional (3D) Finite Element Method (FEM) based strain simulations together with a proposed fabrication methodology provides a guideline for the realization of the structure. Furthermore, 3D Finite Difference Time Domain (FDTD) simulations demonstrate that the designed structure is suitable for the room-temperature lasing in a wavelength range of 2410–2570 nm. 3D FEM-based heat transfer simulations performed for the designed cavity verifies the eligibility of the room-temperature operation paving the way for a possible demonstration of on-chip laser that could take part in the fully integrated infrared systems for a variety of applications including biological and chemical sensing, as well as security such as alarm systems and free-space optical communications. [ABSTRACT FROM AUTHOR]

The PBE-GGA (Perdew Burke-Ernzerhof Generalized Gradient Approximation) for the exchange-correlation potentials, based on first-principles density functional theory (DFT) study is used to investigate the structural, optical, and electrical aspects of XSnI3 (X = Rb, K, Tl, and Cs) materials. According to the DFT calculation, the energy band gaps (Eg) of XSnI3 (X = Rb, K, Tl, and Cs) materials are 2.76, 2.01, 1.90, and 0.34 eV respectively. The direct energy bandgap (Eg) indicates that halide perovskite materials are appropriate semiconductors for solar cell application. A thorough analysis of optical conductivity indicates that, the optical conductance peaks of XSnI3 (X = Rb, K, Tl, and Cs) halide perovskite materials reach maximum values of 2.3, 2.2, 4.5, and 5.2 eV, respectively, in the ultraviolet spectrum and shift slightly at higher energy bands. The maximal optical conductivity of XSnI3 (X = Rb, K, Tl, and Cs) materials were (1.6 × 105 Ω−1 cm−1, 1.8 × 105 Ω−1) cm−1, 2.2 × 105 Ω−1 cm−1 and 2.4 × 105 Ω−1 cm−1 respectively. The XSnI3 (X = Rb, K, Tl, and Cs) is a group of materials with enhanced surface area for light photon absorption and enhanced optical conductivity, energy absorption, and refractive index properties make them suitable for perovskite solar cell application. Highlights: The PBE-GGA (Perdew Burke-Ernzerhof Generalized Gradient Approximation) for the exchange-correlation potentials, based on first-principles density functional theory (DFT) study is used to investigate the structural, optical, and electrical aspects of XSnI3 (X = Rb, K, Tl, and Cs) materials. According to the DFT calculation, the energy band gaps (Eg) of XSnI3 (X = Rb, K, Tl, and Cs) materials are 2.76, 2.01, 1.90, and 0.34 eV respectively. The direct energy bandgap (Eg) indicates that halide perovskite materials are appropriate semiconductors for solar cell application. A thorough analysis of optical conductivity indicates that the optical conductance peaks of XSnI3 (X = Rb, K, Tl, and Cs) halide perovskite materials reach maximum values of 2.3, 2.2, 4.5, and 5.2 eV, respectively, in the ultraviolet spectrum and shift slightly at higher energy bands. The XSnI3 (X = Rb, K, Tl, and Cs) is a group of materials with enhanced surface area for light photon absorption and enhanced optical conductivity, energy absorption, and refractive index properties make them suitable for perovskite solar cell application. [ABSTRACT FROM AUTHOR]

We have proposed leaky integrate-and-fire (LIF) neuron having low-energy consumption and tunable functionality without external circuit components. Our LIF neuron has a simple configuration consisting of only three components: one bandgap-engineered resistive switching transistor (BE-RST), one capacitor, and one resistor. Here, the crucial point is that BE-RST with a silicon–germanium heterojunction possesses an amplified hysteric current switching with a low latch-up voltage due to improved hole storage capability and impact ionization coefficient. Therefore, the proposed neuron utilizing BE-RST requires an energy consumption of 0.36 pJ/spike, which is approximately six times lower than 2.08 pJ/spike of pure silicon-RST based neuron. In addition, the spiking properties can be tuned by modulating the leakage rate and threshold through gate bias, which contributes to energy-efficient sparse-activity and high learning accuracy. As a result, our proposed neuron can be a promising candidate for executing various spiking neural network applications. [ABSTRACT FROM AUTHOR]

Regulating the bandgap edge and building oxygen vacancy (OV) engineering are effective countermeasures for facilitating interfacial charge carrier transfer/separation. Herein, bandgap-matched 2D g-C3N4/WO3–xZ-scheme heterojunction nanocomposites were fabricated using the pyrolysis method with bulk g-C3N4 and WO3 nanorods. Meanwhile, the bandgap edge of g-C3N4 is being fine-tuned, while the OVs in WO3 are deliberately engineered. Satisfactory results were achieved, wherein the photodegraded MO by the 2D g-C3N4/20.0 wt % WO3–xZ-scheme heterojunction nanocomposite was 6.36, 3.78, and 11.07 times higher than that of bulk g-C3N4, 2D g-C3N4, and WO3–x, respectively. Additionally, the photoreduction of Cr (VI) of the former was 8.92, 5.23, and 14.76 times higher than that of the latter three, respectively. There are two primary reasons for the notable increase in the photocatalytic rate: first, through secondary pyrolysis, g-C3N4 can attain a bandgap structure that matches the bandgap of WO3; second, WO3 can generate chippy OV active centers. Furthermore, the synergistic interaction between the two components generates additional interface charges and promotes increased photon absorption, ultimately enhancing the photocatalytic rate. This study offers insights into designing and constructing g-C3N4Z-scheme heterojunction nanocomposites through bandgap and OV engineering for visible-light-driven wastewater purification. [ABSTRACT FROM AUTHOR]

The bandgap engineered MnWO4 nanoparticles doped with Ag were developed using a facile one-pot synthesis method. The impurity doping concentration of Ag was varied from 1 to 5 wt percentages to tune the interactions between manganese tungstate and silver ions to obtain desirable magnetic and optoelectronic properties. The structural properties of the MnWO4 particles with various concentrations of Ag were investigated using X-ray diffraction. The optical properties of the pristine and Ag-doped MnWO4 particles were determined using UV‒Vis and photoluminescence spectroscopy. The impurity concentration-dependent structural transformations and changes in the vibrational modes, lattice dynamics, electronic transitions and optoelectronic properties of the prepared materials were analyzed using Raman spectroscopy. The topology, morphology and elemental analysis of the synthesized nanoparticles were elucidated using HRTEM, SAED, SEM and EDX techniques. The magnetic properties of the MnWO4:Ag nanoparticles were measured using a vibrating sample magnetometer (VSM). The obtained results suggested that Ag-doped MnWO4 nanosystems show enhanced and tunable magnetic properties suitable for nanodilute magnetic semiconductor (nDMS) applications. The presented work opens a range of possibilities for the development of advanced materials with applications in optoelctronics, nanomedicine, energy-efficient electronic devices and energy conversion.

Ultraviolet (UV) radiation poses risks to both human health and organics. In response to the urgent demand for UV-shielding across various applications, extensive endeavors have been dedicated to developing UV-shielding materials spanning from wide-bandgap semiconductors to organo-inorganic composite films. However, existing UV shielding materials, though suitable for daily use, cannot meet the demands of extreme conditions. In this work, we incorporated CeO2 as a UV absorber into Y2O3 transparent ceramics for UV-shielding. The effect of CeO2 concentration on the optical, mechanical, and thermal properties of Y2O3 ceramics was systematically investigated. These findings indicate that CeO2 serves not only as a UV absorber but also as an effective sintering aid for Y2O3 transparent ceramics. The 5 at% Ce-doped Y2O3 transparent ceramics exhibit the optimal optical quality, with in-line transmittance of ~77% at 800 nm. The introduction of Ce shifted the UV cutoff edge of Y2O3 transparent ceramics from 250 to 375 nm, which was attributed to the visible band absorption of Ce4+. This shift grants UV shielding capabilities to Y2O3 transparent ceramics, resulting in 100% shielding for ultraviolet C (UVC, 100–280 nm) and ultraviolet B (UVB, 280–320 nm) and ~95% shielding for ultraviolet A (UVA, 320–400 nm). The service stability (optical properties) under various corrosive conditions (acid, alkali, UV irradiation, and high temperature) was investigated, confirming the excellent stability of this transparent ceramic UV-shielding material. A comparison of the performance parameters of transparent ceramics with those of traditional UV shielding materials such as glasses, films, and coatings was conducted. Our work provides innovative design concepts and an effective solution for UV-shielding materials for extreme conditions.

Solid‐state structures with the superhalogen [BO2]− have thus far only been observed with a few compounds whose syntheses require high reaction temperatures and complicated procedures, while their optical properties remain almost completely unexplored. Herein, we report a facile, energy‐efficient synthesis of the first [BO2]‐based deep‐ultraviolet (deep‐UV) transparent oxide K9[B4O5(OH)4]3(CO3)(BO2) ⋅ 7H2O (KBCOB). Detailed structural characterization and analysis confirm that KBCOB possesses a rare four‐in‐one three‐dimensional quasi‐honeycomb framework, with three π‐conjugated anions ([BO2]−, [BO3]3−, and [CO3]2−) and one non‐π‐conjugated anion ([BO4]5−) in the one crystal. The evolution from the traditional halogenated nonlinear optical (NLO) analogues to KBCOB by superhalogen [BO2]− substitution confers deep‐UV transparency (<190 nm), a large second‐harmonic generation response (1.0×KH2PO4 @ 1064 nm), and a 15‐fold increase in birefringence. This study affords a new route to the facile synthesis of functional [BO2]‐based oxides, paving the way for the development of next‐generation high‐performing deep‐UV NLO materials. [ABSTRACT FROM AUTHOR]

The need for pollution-free energy generation and water treatment is urgent, but more significantly, affordable energy supplies are currently the focus of study. Hydrogen is one of the energy sources that is thought to be pure and clean. This work uses N, F-codoped SnO2 nanoparticles for photocatalytic hydrogen production and dye degradation. At room temperature, a straightforward synthetic method based on solutions has been used to easily incorporate N and F into the SnO2 lattice. Utilizing various scavengers, the photocatalytic water splitting process was carried out. A combination of sacrificial agents was used to get the highest possible hydrogen output. Numerous methods were employed to characterize the generated nanoparticles. Using powder X-ray diffraction and electron microscopy, the phase identity and surface characteristics of the N, F-codoped SnO2 nanoparticles were verified, whereas the elemental percentage composition was confirmed through X-ray photoelectron spectroscopy. A wide bandwidth is seen in the Raman spectra, which suggests the presence of oxygen vacancies and structural disorder brought about by the addition of N and F dopants. In light of this, this work investigates the possibility of N, F-codoped SnO2 as a photocatalyst for photocatalytic hydrogen generation and creates new avenues for the production of energy and environmental concerns. [ABSTRACT FROM AUTHOR]

Graphene (GR) has considered to be a promising material to build proficient graphene-doped composites photocatalyst with superior catalytic activities for wastewater treatment. During the past decade, different graphene-doped composites have been constructed and applied in numerous solar and photocatalyst fields. GR-based composites have a sufficient surface area with numerous photocatalytic sites for wastewater treatment applications. In the present study the effect of hetero-atoms Aluminum, Nitrogen, and Boron on bandgap engineering and tuning of electronic and optical properties of GR-doped-composites by density functional quantum computing calculation. Our computed results demonstrate that hetero-atoms-doped-GR composites having direct energy band (Eg) semiconductor nature with an increment from 0.0 to 1.75 eV by the inclusion of hetero-atoms in GR, maybe some extra strong sites are formed in p state into the lifting of the energy bandgap (Eg). An extensive investigation of optical conductivity illustrates that increment in peaks from 2.5 to 4.0. Due to hetero-atoms dopant the absorbance peaks are increased and moved toward higher energy absorption. Our findings reveal that as compared to pure, Al, N,B hetero-atoms, the B-doped-GR surface has a large surface area with strong active sites for wastewater treatment. These theoretical findings can be useful in practical applications for wastewater remediation through hetero-atom-doped graphene composites. [ABSTRACT FROM AUTHOR]

A facilely topochemical-like reduction method is used to prepare narrow bandgap bismuth thiooxide and use it for tumor phototherapy under near-infrared light. [Display omitted] The physical property tuning of nanomaterials is of great importance in energy, medicine, environment, catalysis, and other fields. Topochemical synthesis of nanomaterials can achieve precise control of material properties. Here, we synthesized a kind of element-doped bismuth-based nanomaterial (BOS) by topochemical-like synthesis and used it for the phototherapy of tumors. In this study, we employed bismuth fluoride nanoflowers as a template and fabricated element-doped bismuth oxide nanoflowers by reduction conditions. The product is consistent with the precursor in crystal structure and nanomorphology, realizing topochemical-like synthesis under mild conditions. BOS can generate reactive oxygen species, consume glutathione, and perform photothermal conversion under 730 nm light irradiation. In vitro and in vivo studies demonstrate that BOS could suppress tumor growth by inducing apoptosis and ferroptosis through phototherapy. Therefore, this study offers a general regulation method for tuning the physical properties of nanomaterials by using a topochemical-like synthesis strategy. [ABSTRACT FROM AUTHOR]

Extensive research has been conducted on silver niobite (AgNbO 3)-based antiferroelectric ceramics for their promising applications in energy storage applications, with various compositional modifications explored to improve their energy storage capabilities. In this theoretical study, we have systematically investigated the electronic, structural, and chemical bonding properties of AgNb 1- x Ta x O 3 (x = 0.00, 0.125, 0.25, 0.375, 0.50, abbreviated as ANT100 x) solid solutions based on first-principles calculation. Our results reveal that the bandgap increases from 1.82 eV to 1.89 eV, due to the higher energy level of Ta 5 d orbitals compared to Nb 4 d orbitals. The enlarged bandgap, accompanied with oxygen vacancy formation energy (Δ E f , v a c ), contributes to the enhancement of E b. The Ta substitution of Nb site suppresses the cation displacement, oxygen octahedral distortion, and bond length and angles, indicating an improved stability of antiferroelectric phase. In addition, the electron localization function (ELF) and Bader charge values show weakened covalent bonding of Ta−O bonds compared to Nb−O bonds. These theoretical findings have the potential to aid in the advancement and creation of novel energy storage applications using lead-free AFE perovskites, as well as facilitate the manipulation of their breakdown electric field through bandgap engineering. [ABSTRACT FROM AUTHOR]

Platelet‐shaped zinc oxide (ZnO) particles exhibit certain advantages compared to conventional micron and nano forms. Their superior surface coverage and excellent optical properties make these particles very attractive as UV filters in cosmetics and personal care applications. Although ZnO is non‐toxic, it exhibits photocatalytic activity (PCA), which increases when the size of particles approaches the nanoscale. High PCA of mineral/inorganic filters is not desired in cosmetics and personal care applications. Therefore, it is essential to develop strategies to reduce PCA of such materials under UV exposure. Accordingly, the research objective of this study is to develop an understanding of the effects of Co‐doping on the optoelectronic and crystal structure of platelet shaped ZnO particles with Zn1‐xMxO stoichiometry (x=0‐4 wt % cobalt). XRD‐based Rietveld refinement and WD‐XRF reveal that Co was successfully doped into the ZnO lattice. SEM and particle size analyses confirmed that the shape and size of the designed ZnO platelets did not change significantly after doping. ~85 % reduction in PCA has was achieved by 3 wt % Co doping which was attributed to reduced OH and O2 free radical concentration. These results clearly show that Co‐doping can be used to effectively tailor the bandgap and optical properties of the designed ZnO particles. [ABSTRACT FROM AUTHOR]

For high‐performance application of perovskite solar cells (PSCs) in monolithic perovskite/silicon tandem configuration, an optimal bandgap and process method of the perovskite top cell is required. While the two‐step method leads to regular perovskite film crystallization, engineering wider bandgaps (Eg > 1.65 eV) for the solution‐based two‐step method remains a challenge. This work introduces an effective and facile strategy to increase the bandgap of two‐step solution‐processed perovskite films by incorporating bromide in both deposition steps, the inorganic precursor deposition (step 1, PbBr2) and the organic precursor deposition (step 2, FABr). This strategy yields improved charge carrier extraction and quasi‐Fermi level splitting with power conversion efficiencies (PCEs) of up to 15.9%. Further improvements are achieved by introducing CsI in the bulk and utilizing LiF as surface passivation, resulting in a stable power output exceeding 18.5% for Eg = 1.68 eV. This additional performance boost arises from enhanced perovskite film crystallization, leading to improved charge carrier extraction. Laboratory scale monolithic perovskite/silicon solar cells (TSCs) (1 cm2 active area) achieve PCEs up to 23.7%. This work marks a significant advancement for wide bandgap two‐step solution‐processed perovskite films, enabling their effective use in high‐performance and reproducible PSCs and perovskite/silicon TSCs. [ABSTRACT FROM AUTHOR]

The double gradient bandgap absorber has the potential to enhance carrier collection, improve light collection efficiency, and make the performance of solar cells more competitive. However, achieving the double gradient bandgap structure is challenging due to the comparable diffusion rates of cations during high‐temperature selenization in kesterite Cu2ZnSn(S,Se)4 (CZTSSe) films. Here, it has successfully achieved a double gradient bandgap in the CZTSSe absorber by spin‐coating the K2S solution during the preparation process of the precursor film. The K2S insertion serves as an additional S source for the absorber, and the high‐affinity energy of K‐Se causes the position of the spin‐coated K2S solution locally Se‐rich and S‐poor. More importantly, the position of the bandgap minimum (notch) and the depth of the notch can be controlled by varying the concentration of K2S solution and its deposition stage, thereby avoiding the electronic potential barrier produced by an inadvertent notch position and depth. In addition, the K─Se liquid phase expedites the selenization process to the elimination of the fine grain layer. The champion CZTSSe device achieved an efficiency of 13.70%, indicating the potential of double gradient bandgap engineering for the future development of high‐efficiency kesterite solar cells. [ABSTRACT FROM AUTHOR]

Decreasing the power consumption of light‐emitting diodes (LEDs) and increasing the energy generation of solar cells are crucial tasks toward the mitigation of greenhouse gas emissions and Paris Agreement goals. Lead (Pb)‐free halide double perovskites, identified as environmentally friendly alternatives to Pb‐based perovskites, are not deemed useful thus far due to the absence of high photoluminescence quantum yield (PLQY) examples and large bandgaps. Herein, penta‐cationic antimony (Sb5+)‐doping strategy is demonstrated for the benchmark material of Cs2NaInCl6, achieving blue emission with near‐unity PLQY and the lowest bandgap of 1.24 eV. The excellent PLQY observed in the material is attributed to Sb5+ doping‐induced Jahn–Teller distortion in Cs2NaInCl6 and a newly emerged band structure, which has remained undisclosed in all previous reports. This groundbreaking discovery represents the first instance in the field of perovskite materials where the incorporation of a single dopant has resulted in a zero‐to‐one enhancement in their emission profile. This breakthrough is expected to have profound implications for advancing research in the utilization of similar dopants, such as manganese cations (Mn6+ and Mn7+), not only in halide perovskite structures but also in oxide‐based perovskites and other semiconductor systems. [ABSTRACT FROM AUTHOR]

In early twenty-first century, 2D materials are among the most systematically reachable in the field of material science. Due to its semiconductor properties, the transition metal dichalcogenide family has received attention. In the current research, the GGA-PBE simulation approximation is used to tune energy bandgap (Eg), optical and electronic properties of TMDCs (transition metal dichalcogenide) such as WS2, PtS2, MoS2, WSe2, PtSe2, and MoSe2 by density functional quantum computing simulation. It is calculated that the energy bandgap (Eg) of WSe2, PtSe2, and MoSe2 shows a decrement trend with small Eg 1.43, 0.88, and 0.74 eV respectively as compared to WS2, PtS2, and MoS2 with large Eg 1.96, 1.62, and 1.50 eV respectively with direct to indirect semiconductor nature. In WSe2, PtSe2, and MoSe2 materials the extra gamma active states created which help to build the conduction and valance bands as a consequence of decrement in the Eg. A detailed study of optical conductivity shows that optical conductance increases with bandgap decrement (1.96–0.74 eV) in ultraviolet pattern with small shifts at larger energy bands. 2D-TMDCs MoS2 and MoSe2 shows maximum optical conductivity and absorbance 105 × 103Ω−1 cm−1, 2.78 × 105 cm−1 and 85 × 103Ω−1 cm−1, 3.1 × 105 cm−1 respectively as compared to WS2, PtS2, WSe2 and PtSe2 due to small energy bandgap. In the reflectivity, a significant increment is found in MoS2 and MoSe2 semiconductor materials as compared to WS2, PtS2, WSe2, and PtSe2 due to the decrement in the bandgap. The family of TMDCs such as WS2, PtS2, MoS2, WSe2, PtSe2, and MoSe2 are a capable semiconductors materials has a enhanced surface area for absorbance of photo-generated charge carriers and decrease the photo-generated charge carriers recombination rate and increment the charge transportation. The optical properties significantly enlarged MoS2 and MoSe2 materials have proficient energy absorbance, and refractive index as compared to WS2, PtS2, WSe2, and PtSe2 semiconductors, and all these materials are appropriate for photocatalytic and solar cell applications. [ABSTRACT FROM AUTHOR]

Quinoid single molecules are regarded as promising materials for electronic applications due to their tunable chemical structure-driven properties. A series of three single bio-inspired quinoid materials containing para-azaquinodimethane (p-AQM) moiety were designed, synthesized and characterized. AQM1, AQM2 and AQM3, prepared using aldehydes derived from almonds, corncobs and cinnamon, respectively, were studied as promising quinoid materials for optoelectronic applications. The significance of facile synthetic procedures is highlighted through a straightforward two-step synthesis, using Knoevenagel condensation. The synthesized molecules showed molar extinction coefficients of 22,000, 32,000 and 61,000 L mol−1 cm−1, respectively, for AQM1, AQM2 and AQM3. The HOMO-LUMO energy gaps were calculated experimentally, theoretically showing the same trends: AQM3 < AQM2 < AQM1. The role of the aryl substituent was studied and showed an impact on the electronic properties. DFT calculations show planar structures with quinoidal bond length alternation, in agreement with the experimental results. Finally, these bio-based materials showed high thermal stabilities between 290 °C and 340 °C and a glassy behavior after the first heating–cooling scan. These results highlight these bio-based single molecules as potential candidates for electronic or biomedical applications. [ABSTRACT FROM AUTHOR]

Unlike conventional opaque solar cells, semi‐transparent solar cells enable simultaneous electricity generation and light transmission. Along with solar energy harvesting, the offered multiple functionalities of these technologies, such as aesthetic appearance, visual comfort and thermal management, open diverse integration opportunities into versatile technological applications. In this work, the first demonstration of a novel semi‐transparent solar cell based on ultrathin hydrogenated amorphous Si/Ge multiple quantum wells (MQW) is reported. Through optoelectronic modelling, the advantages of ultrathin MQW as photoactive material to overcome the intrinsic limitations of thin (20 nm) and ultrathin (2.5 nm) single quantum well (SQW) counterparts are explained. This allows extra degree of freedom for both optical design and bandgap engineering. Mainly, the multiplication of the QWs number in a periodic configuration, taking advantage of effective synergy between electronic and photonic confinements, leads to an improvement of photocurrent, while preserving high voltage and fill factor and ensuring significant transparency. The MQW new concept yields a boost in power conversion efficiency up to 3.4% and a considerable average visible transmission of about 33%. A light utilization efficiency above 1.1% is achieved, which can be considered as one of the highest among inorganic semi‐transparent solar cell technologies. The successful demonstration of ultrathin semi‐transparent Si/Ge MQW solar cells indicates the promising integration potential of this emerging photovoltaic technology for supplying systems in relevant applications such as in buildings, vehicles and greenhouses. [ABSTRACT FROM AUTHOR]

The research's primary objective is to successfully utilize the sol-gel method to synthesize FeVO 4 /h-BN nanocomposite with a smaller bandgap than h-BN (hexagonal boron nitride). The nanocomposite was examined using various techniques, including XRD, SEM, TEM, UV–Vis, PL, FT-IR, XPS, EIS, and Mott-Schottky analysis, to properly evaluate its structure, optical activity, vibrational properties, chemical compositions, and electrochemical studies. The FeVO 4 /h-BN binary nanocomposite shifts the band gap of synthesized h-BN from 5.8 eV to 2.01 eV. The composite's morphology made it abundantly clear that the spherical FeVO 4 was anchored together in a sheet of h-BN. A phytotoxicity test was conducted after the photocatalytic degradation of industrial wastewater from textiles. Correspondingly, interpretation of the photocatalytic process showed the FeVO 4 /h-BN nanocatalyst degraded against industrial wastewater (IWW), Congo red (CR), and Methylene blue (MB) dye by up to 92.5%, 86.4%, and 96.4%, and antibiotics like metronidazole (MNZ) and cephalexin (CPX) up to 95.8% and 83.5% respectively, within 60 min under visible light. Numerous Physiochemical parameters intensity in the degraded IWW had greatly reduced, denoting lessened toxicity. To understand the photocatalytic degradation mechanism, trapping experiments with different scavengers were pursued. The scavenger study's evidence suggests that holes (h+) deserve greater suspicion for the degradation process. The material's potential for recycling was examined, and it was found to have significant potential insight into recycling prospects. In actual textile wastewater, the FeVO 4 /h-BN degrading tactic proved itself to be an efficient as well as economical choice. [Display omitted] [ABSTRACT FROM AUTHOR]