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The growing demand for real-time ultraviolet (UV) monitoring calls for a simple, rapid, and low-cost strategy to prepare UV photodetectors (PDs). We prepare a wearable real-time UV PD based on hydrogenated titanium dioxide film synthesized by radio frequency atmospheric pressure plasma. The conductivity of our hydrogenated titanium dioxide is improved to 10.2 S cm−1, nine orders of magnitude higher than that of pristine titanium dioxide after 10 min plasma treatment. Plasma hydrogenation disrupts the surface crystal structure, introducing oxygen vacancies (OVs) that create self-doped titanium(III) and titanium(II) species. First-principles calculations indicate that the OVs raise the Fermi level of TiO2 and distort the lattice locally. Our optimized film has a distinctive periodic switching characteristic under intermittent illumination; its responsivity is good from 280 to 400 nm, peaking at 632.35 mA W−1 at 365 nm. The fabricated wearable sensor based on the optimized film effectively monitors the daily variation of ambient UV intensity in three typical weather types, transferring its data to a smartphone via Wi-Fi. [ABSTRACT FROM AUTHOR]

Polymers containing lactam structures play a crucial role in both natural biological systems and human life, and their synthesis, functions and applications are of utmost importance for biomimetics and the creation of new materials. In this study, we developed an efficient heterogeneous Pauson–Khand polymerization (h‐PKP) method for the controlled synthesis of main‐chain poly(γ‐lactam)s containing α, β‐unsaturated γ‐lactam functionalities using readily available internal alkynes and imines. The molecular weights of the resulting poly(N−Ts/γ‐lactam)s can be precisely controlled by adjusting the ratio of phenyl formate and nickel. These polymers exhibit high solid‐state luminescence and demonstrate rapid and sensitive dual responsiveness to light and acid stimuli. They further demonstrate strong reactive oxygen species (ROS) generation capability. The unique dual‐emission peaks observed in poly(N−H/γ‐lactam)s obtained through post‐treatment under acidic conditions demonstrate a mechanism of aggregation‐induced intermolecular excited‐state proton transfer specific to lactam structures. The efficient one‐pot synthetic method for poly(γ‐lactam) provides a novel strategy for constructing polymers with γ‐lactam structures in the main chain and the simple and efficient post‐modification method offer a versatile toolbox for functionalizing poly(γ‐lactam)s to expand their potential applications. [ABSTRACT FROM AUTHOR]

Organometallic halide perovskites have shown significant promise for applications in optoelectronics and photovoltaics in recent years. This research looks into the performance of bulk heterojunction-based photodetectors (PDs) based on the active layer of a CH3NH3PbI3:PCBM bulk heterojunction (BHJ). We assessed the impact of PCBM concentration in CH3NH3PbI3:PCBM BHJ on the electrical performance of the PDs. We found that the BHJ PD with a 4% PCBM concentration had the strongest capability to reject noise, as demonstrated by its superior ratio of photocurrent to dark current. Moreover, the PD with a 4% PCBM concentration in the active layer outperforms pristine CH3NH3PbI3-based PDs in terms of optoelectronic performance, showing greater responsivity and detectivity. The improved optoelectronic performance of BHJ PD is due to increased interfacial area, higher electron extraction and a decrease in traps and defects. The analysis of dark current–voltage curves reveals a significant reduction in charge recombination for BHJ devices, supporting the elimination of traps and defects by the inclusion of PCBM. The PD’s impedance study unveils that the incorporation of PCBM enhances charge transfer and effectively suppresses charge recombination, leading to enhanced optoelectronic performance. [ABSTRACT FROM AUTHOR]

Hydrogen-bonded organic frameworks (HOFs) are a recent class of porous materials that have garnered considerable research interest owing to their distinctive characteristics. HOFs can be constructed through judicious selection of H-bonding motifs, which are further enforced by other weak intermolecular interactions such as π–π stacking, van der Waals forces, and framework interpenetration. Taking advantage of these interactions, we can expand the functional field of HOFs by introducing active molecules. Recently, researchers have made substantial advancements in using HOFs for chemical sensing, catalysis, proton conduction, biological applications, and others. The low bonding energy of H-bonds allows for precise control over the concentration of ligands in solvents, forming diverse HOF structures. These varied structures offer significant advantages for producing HOFs with photo-responsive and electro-responsive properties. However, the presence of H-bonds in HOFs results in their inherent lower stability compared to metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) formed via coordination and covalent bonds, respectively. As a result, the pursuit of stable and innovative HOF materials with novel functional sites remains an ongoing challenge. This review provides an overview of recent research progress in the development of new strategies for stable HOF synthesis and applications of HOFs with stimuli-responsive properties. We first classified all synthetic methods reported to date and discussed the stable HOFs synthesized, as well as their unique properties and applications. In addition, we summarized the applications of HOFs utilizing their synergistic responses to external stimuli, including photo, electrical, pressure, and chemical stimuli. We systematically reviewed stable HOF synthesis and applications, which may lead to a deeper understanding of the structure–activity relationship for these materials and guide future HOF design. [ABSTRACT FROM AUTHOR]

To date, smart surfaces with controllable wettability have received extraordinary attention due to their great importance in both fundamental research and practical applications. Chemical composition and surface topography are the two key factors to affect the wettability of solid surfaces. Applying external stimuli to change the surface chemistry and/or topography is considered to be a valuable approach for driving the transition between hydrophilicity and hydrophobicity of surfaces. In this study, poly o-toluidine nanofibers were synthesized by a facile aqueous/organic interfacial polymerization, and superhydrophobic coatings of poly o-toluidine were prepared via a room-temperature spraying process. The reversible wettability conversion between the superhydrophobic and the hydrophilic state of the obtained poly o-toluidine coating under ultraviolet irradiation and electric stimulation was investigated. From the X-ray photoelectron spectroscopy analysis, this intelligent switching wetting behavior under ultraviolet light irradiation was confirmed to have a high correlation with the change in surface chemical composition. When the electric stimulation was applied, the wettability switch was caused by the redistribution of charge and electric dipole along the liquid–solid interface. [ABSTRACT FROM AUTHOR]

Abstract The smart emulsification and demulsification system with the light response is a useful tool in various industries, including green chemistry, catalytic reaction, pharmaceuticals, and environmental remediation. Herein, an ionic liquid crystal compound with a light triggered switch based on the azobenzene group [(4‐{3‐methyl‐1‐[3‐(8‐octyloxyoctyl)oxy‐4‐oxobutanoyl]imidazo‐lium‐1‐yl}octyl)oxy] ‐N‐(4‐methylphenyl)benzene‐1,2‐diazene bromide (MOIAzo), was designed and synthesized, which could cause reversible transition between emulsification and demulsification through the light trigger. The ionic liquid has an efficient photoinduced liquefaction process, which dramatically lowers the melting point of ionic liquids from 79 to 9.2 oC. This significantly broadens the liquid state temperature of the ionic liquid crystal. The ionic liquid crystal MOIAzo exhibits both photoinduced and thermally induced nematic liquid crystal properties. The smart emulsion system was effectively employed in an eco‐friendly water‐saving dyeing process of cationic dyes for cationic dyeable polyester (CDP) fabrics, which used only half the amount of water compared with the conventional water bath dyeing method. After dyeing, the oil and water phases can be efficiently separated through the light irradiation, and the oil phase can be reused for the subsequent dyeing process. This novel smart emulsion dyeing method greatly reduces the water consumption and wastewater discharge. MOIAzo as a light‐triggered ionic liquid molecule opens up new dimensions in green chemistry.

In this work, an 8×8 Ga2O3 solar-blind ultraviolet photodetector array is introduced for image sensing application. The 2-in wafer-scaled Ga2O3 thin film was grown by metalorganic chemical vapor deposition technique; and the photodetector array was fabricated through ultraviolet photolithography, lift-off, and electron-beam evaporation. In addition to the high solar-blind/visible rejection ratio of 104, every photodetector cell in the array has high performance and fast response speed, such as responsivity of 49.4 A W−1, specific detectivity of 6.8 × 1014 Jones, external quantum efficiency of 1.9 × 104%, linear dynamic range of 117.8 dB, and response time of 41 ms, respectively, indicating the high photo-response performance of the photodetector. Moreover, the photodetector array displayed uniform responsivity with a standard deviation of ∼6%, and presented a sensing image of low chromatic aberration, owing to the high resolution of the photodetector array. In a word, this work may contribute to developing Ga2O3-based optoelectronic device applications. [ABSTRACT FROM AUTHOR]

Many hydrogel patches are developed to solve the pervasive and severe challenge of complex wound healing, while most of them still lack satisfactory controllability and comprehensive functionality. Herein, inspired by multiple creatures, including octopuses and snails, a novel muti‐functional hydrogel patch is presented with controlled adhesion, antibacterial, drug release features, and multiple monitoring functions for intelligent wound healing management. The patch with micro suction‐cup actuator array and a tensile backing layer is composed of tannin grafted gelatin, Ag‐tannin nanoparticles, polyacrylamide (PAAm) and poly(N‐isopropylacrylamide) (PNIPAm). In virtue of the photothermal gel‐sol transition of tannin grafted gelatin and Ag‐tannin nanoparticles, the patches exert a dual anti‐microbial effect and temperature‐sensitive snail mucus‐like features. In addition, as the "suction‐cups" consisting of thermal responsive PNIPAm can undergo a contract‐relax transformation, the medical patches can adhere to the objects reversibly and responsively, and release their loaded vascular endothelial growth factor (VEGF) controllably for wound healing. More attractively, benefiting from their fatigue resistance, self‐healing ability of the tensile double network hydrogel, and electrical conductivity of Ag‐tannin nanoparticles, the proposed patches can report multiple wound physiology parameters sensitively and continuously. Thus, it is believed that this multi‐bioinspired patch has immense potential for future wound healing management. [ABSTRACT FROM AUTHOR]

Abstract Many hydrogel patches are developed to solve the pervasive and severe challenge of complex wound healing, while most of them still lack satisfactory controllability and comprehensive functionality. Herein, inspired by multiple creatures, including octopuses and snails, a novel muti‐functional hydrogel patch is presented with controlled adhesion, antibacterial, drug release features, and multiple monitoring functions for intelligent wound healing management. The patch with micro suction‐cup actuator array and a tensile backing layer is composed of tannin grafted gelatin, Ag‐tannin nanoparticles, polyacrylamide (PAAm) and poly(N‐isopropylacrylamide) (PNIPAm). In virtue of the photothermal gel‐sol transition of tannin grafted gelatin and Ag‐tannin nanoparticles, the patches exert a dual anti‐microbial effect and temperature‐sensitive snail mucus‐like features. In addition, as the “suction‐cups” consisting of thermal responsive PNIPAm can undergo a contract‐relax transformation, the medical patches can adhere to the objects reversibly and responsively, and release their loaded vascular endothelial growth factor (VEGF) controllably for wound healing. More attractively, benefiting from their fatigue resistance, self‐healing ability of the tensile double network hydrogel, and electrical conductivity of Ag‐tannin nanoparticles, the proposed patches can report multiple wound physiology parameters sensitively and continuously. Thus, it is believed that this multi‐bioinspired patch has immense potential for future wound healing management.

The poly[N,N-(dimethylamino) ethyl methacrylate] (PDMAEMA) macro-RAFT agent mediated dispersion polymerization of photo-responsive nitrobenzene-based monomer of o-nitrobenzyl methacrylate (NBMA) was performed and the polymerization kinetics and evolution of the block copolymer nanoparticles morphology during the RAFT dispersion copolymerization were investigated in detail. This dispersion RAFT polymerization underwent initial homogeneous polymerization at initial stage and then a subsequent stage of slowed heterogeneous polymerization occurred until the monomer conversion of the polymerization reaction is basically unchanged at about 50% at 24 h. The reason of deceleration of the second stage that is different from the second stage of acceleration for common monomer is discussed. The PDMAEMA-b-PNBMA nanoparticles were prepared by PDMAMEA-mediated RAFT dispersion polymerization, and the photo-response of PDMAEMA-b-PNBMA nanoparticles was also studied. [ABSTRACT FROM AUTHOR]

This research explores the novel photo-response properties of cobalt (Co) doped cadmium sulfide (CdS) thin films developed using a facile and cost-effective spray coating technique. The microstructural parameters were evaluated using XRD patterns and the estimated values of crystallite sizes, lattice strains, dislocation densities and induced stress were found to be in the range of 16.1–25.9 nm, 5.9 × 10−3-3.4 × 10−3, 3.8 × 10−3-1.4 × 10−3 and 3.4–1.9 (GPa) for undoped and Co:CdS films, respectively. The optical band gap energies were found to be 2.369, 2.454, 2.469, and 2.501 eV for undoped, 1 wt. %, 3 wt. %, and 5 wt. % Co: CdS films, respectively using Tauc's plots. The values of extinction coefficient (k) and refractive index (n) were observed in the range of 0.45–0.69 and 2.72–3.05 for as-prepared thin films. Photocurrent (Iph)-applied voltage (V) characteristic of the prepared thin films was measured under visible light condition of low power densities (0.15, 0.25, 0.50, 1.57, 2.50 and 5.0 mW/cm2). A remarkable photosensitivity of 0.165–8.842 × 103 (mW/cm2) at 5.0 mW/cm2 was observed. Saturated surface resistivity of as-prepared thin films was measured for pure CdS, which decreases by increasing Co content. External quantum efficiency (EQE) and Detectivity (DET) were enhanced with Co contents. The values of EQE and DET were found to be 1.0 × 103-2.47 × 1012 and 9.88 × 1012 -2.41 × 1012 for 5.0 wt. % Co: CdS films, respectively at power densities (0.15, 0.25, 0.50, 1.57, 2.50 and 5.0 mW/cm2). Our findings proposed the major role of such prepared films in the fabrication of advanced photodetectors suitable for optoelectronic devices developments.

Transition metal chalcogenides have gained significant attention for their optoelectronic and electrical applications in various fields due to their elemental composition-dependent tunable properties. Here, a facile microwave-assisted approach was used to synthesize different CuSe1–xTe1+x-based nanomaterials. By varying the Se and Te concentrations, the morphology of CuSe1–xTe1+x was tuned from nanosheet-based flowers to nanospheres. With the increase in the value of the Te-to-Se content ratio, the material shows the transition from mixed nanosheets/nanospheres to pure nanospheres, where the average sheet thickness and sphere diameter are ∼25 and 80 nm, respectively. The as-synthesized material shows high crystallinity with mixed phases of hexagonal Cu2Te and CuSe. The chemical bonding of the material exhibits shifts of the spectra toward lower binding energies with the decrease in the Se-to-Te ratio. The material exhibits a change in the absorption edge with a blue shift of the optical bandgap for the increase of the Te content. The increment in the absorption makes them eligible for solar cell application. The photoluminescence spectra of different CuSeTe samples show broad emission in the 550–950 nm range with a peak at ∼700 nm. Such optical properties enable CuSeTe materials for possible applications in optoelectronic devices. The dielectric measurement of the sample exhibits an increase in the dielectric constant and loss with temperature, whereas a decrease in both the values is apparent for increase in the frequency. The dielectric study of the material reveals its potential application for energy storage. The photo-response study demonstrated that the material can be employed for photodetector application. [ABSTRACT FROM AUTHOR]

This research work focuses on the influence of Neodymium (Nd) doping (0–10 at.%) on the structural, optical, electrical, and photo-response properties of Zinc Oxide thin films deposited on glass substrates by cost-effective spray pyrolysis technique. For all the deposited films, the X-ray diffraction peaks matched the hexagonal wurtzite structure of ZnO with the maximum intensity along the (1 0 1) plane. Using XRD data, the crystallite size, dislocation density, and micro-strain of the films were estimated. Compared to other films, Zn0.96Nd0.04O film exhibited higher crystallinity ~ 18 nm. At higher doping concentrations, a fibrous-granular mixed structure was observed. Above 80 percentage of transparency in the visible region and bandgap of 3.42 eV was observed for the Zn0.96Nd0.04O film. The decrease in Urbach energy with increase in the doping concentration indicated the improvement in crystallinity. The peaks related to band edge emission, zinc, and oxygen-related defects were observed in the photoluminescence analysis also increased band edge emission and lesser defects were observed in the Zn0.96Nd0.04O film. The highest charge carrier concentration ~ 1.7 × 1017 cm−3 and mobility ~ 62.8 cm2/Vs were noticed in of Zn0.96Nd0.04O film. When exposed to UV light, Zn0.96Nd0.04O film exhibited the maximum photocurrent ~ 10−4 A. Hence the Zn0.96Nd0.04O film can be used as a UV photodetector. [ABSTRACT FROM AUTHOR]

The nebulizer spray pyrolysis (NSP) technique is employed to analyze the effect of samarium doping on the structural, morphological, optical, and electrical conductivity in Bi2S3 thin films deposited on bare glass substrates by varying the doping concentration from 0 to 3 wt %. Further, their photosensing properties are also studied to utilize the prepared Bi2S3:Sm thin films for photo-detecting applications. The Bi2S3:Sm thin films are found to be in an orthorhombic structure. The data from X-ray diffraction are used to calculate the value of crystallite size, microstrain, and lattice parameters, as well as the volume of the unit cell. 2% Sm-doped Bi2S3 film exhibited a maximum crystallite size of 38 nm and a lower micro-strain value. FESEM micrographs of 2% Sm-doped film show well-defined larger grains. The optical band gap is found to vary between 2.02 and 2.26 eV when the Sm doping concentration is varied. These thin films' absorption is higher around the ultraviolet region of the electromagnetic spectra. The electrical properties exhibited an increase in photocurrent under illumination. A higher responsivity of 9.57 × 10–1 AW–1, detectivity of 1.97 × 1011 Jones, and external quantum efficiency of 309% are recorded for Bi2S3:Sm (2%) thin film. The response and recovery time of the Bi2S3:Sm (2%)-based photodetector are observed to be 1.6 and 1.8 s, respectively. These favorable characteristics of samarium-doped Bi2S3 thin films recommend its potential usage in low-cost, high-performance UV photodetectors. [ABSTRACT FROM AUTHOR]

Thermally induced reversible up/down migration of poly(ionic liquid)s (PILs) in aqueous two‐phase systems (ATPSs) was achieved for the first time in this study. Novel ATPSs were fabricated using azobenzene (Azo)‐ and benzyl (Bn)‐modified PILs, and their upper and lower phases could be easily tuned using the grafting degree (GD) of the Azo and Bn groups. Bn‐PIL with higher GDBn could go up into the upper phase and Azo‐PIL come down to the lower phase when the temperature increased (>65 °C); this behavior was reversed at lower temperatures. Moreover, a reversible two‐phase/single‐phase transition was realized under UV irradiation. Experimental and simulation results revealed that the difference in the hydration capacity between Bn‐PIL and Azo‐PIL accounted for their unique phase‐separation behavior. A versatile platform for fabricating ATPSs with tunable stimuli‐responsive behavior can be realized based on our findings, which can broaden their applications in the fields of smart separation systems and functional material development. [ABSTRACT FROM AUTHOR]

In this present work, copper (II) sulfide (CuS) nanoparticles (NPs) were synthesized via co-precipitation [CuS(co-pr)] and solvothermal [CuS(solv)] methods. The structural, optical, and electrical properties of these materials were analyzed and compared. It was observed that the particle size and crystallinity varied depending on the synthesis method employed. Further, two individual metal-semiconductor junction devices based on CuS(co-pr) and (CuS(solv) were fabricated. Then the current vs. voltage (I–V) measurements were performed. The comparative study of the electrical parameters like photo response, rectification ratio, barrier height and ideality factor were performed between the two synthesized CuS NPs based devices. Under no light condition, the rectification ratio for CuS(solv) increased by 28 % more than that of CuS(co-pr). The photo response for CuS(solv) also enhanced by 146 %. For a better understanding of junction and carrier transport properties space charge limited current (SCLC) theory is incorporated. The interfacial resistance of the devices was studied by Nyquist plots obtained from the impedance spectroscopy and were also fitted by equivalent circuit model and explained the mechanism of charge transport through the Schottky interface. The transit time and carrier mobility were improved for CuS(solv) than CuS(co-pr). Thus, the solvothermally synthesized CuS-based device could be assigned as it possesses lesser number of lattice defects, better crystallinity and larger particle size along with its better film properties leading to better performance. [Display omitted] • Optical absorption edge of CuS(solv) shifted towards the longer wavelength than CuS(co-pr). • CuS NPs synthesized by solvothermal method exhibits improved charge transport and photo response over CuS(co-precipitation). • Fewer carrier recombination through M−S junction make CuS(solv) a better Schottky device over CuS(co-pr). • Lesser lattice defects and better thin film properties enhances performance of CuS(solv) based Schottky diode. [ABSTRACT FROM AUTHOR]

• Novel ATPSs were fabricated using Azo- and Bn-functionalized PILs. • The grafting degrees of Azo and Bn had significant effects on the phase separation of ATPS. • The upper/lower phases of ATPSs with CB[8] could be inverted by photo and thermo stimuli. • The phase separation of ATPSs was regulated by host–guest interaction for the first time. Smart aqueous two-phase systems (ATPS) have aroused tremendous interests in view of their tunable phase behaviors under various stimuli, and found many potential applications in the domain of separation. Herein, poly(ionic liquid)s (PILs), functionalized by benzyl (Bn) and azophenyl (Azo) groups, were prepared through a post-synthesis modification strategy. The as-fabricated ATPSs composing of Azo-PIL and Bn-PIL exhibited a photo- and thermo-responsive two-phase to one-phase transition. However, when the host molecule cucurbituril[8] urea (CB[8]) was introduced, the as-developed PIL-based ATPSs underwent a reversible upper and lower phases inversion behaviors, which could be tuned through light irradiation or heating treatment. The study revealed that both the grafting degree (GD) of Azo/Bn groups and the feeding ratio of CB[8] played a critical role in this switchable phase inversion behavior. In addition, the sensitive hydration ability of functional PILs to external stimuli accounted for the phase inversion behavior of ATPSs. Thereby, our finding offers a novel platform for adjusting the phase separation behaviors of ATPSs via host–guest interactions. [ABSTRACT FROM AUTHOR]

We demonstrated the temporal photo‐response of transparent and flexible carbon nanotube thin‐film transistors. Fabricated carbon nanotube thin film transistors showed exponential degradation with light illumination and linear recovery after light off. The result indicates that the principal mechanism of photo‐response in carbon nanotube transistors is photo‐desorption of oxygen molecules. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive supercapacitors have attracted broad interest in constructing self‐powered smart devices. However, due to the demand for high cyclic stability, supercapacitors usually utilize stable or inert electrode materials, which are difficult to exhibit dynamic or stimuli‐responsive behavior. Herein, this issue is addressed by designing a MoS2@carbon core‐shell structure with ultrathin MoS2 nanosheets incorporated in the carbon matrix. In the three‐electrode system, MoS2@carbon delivers a specific capacitance of 1302 F g−1 at a current density of 1.0 A g−1 and shows a 90% capacitance retention after 10 000 charging‐discharging cycles. The MoS2@carbon‐based asymmetric supercapacitor displays an energy density of 75.1 Wh kg−1 at the power density of 900 W kg−1. Because the photo‐generated electrons can efficiently migrate from MoS2 nanosheets to the carbon matrix, the assembled photo‐responsive supercapacitor can answer the stimulation of ultraviolet‐visible‐near infrared illumination by increasing the capacitance. Particularly, under the stimulation of UV light (365 nm, 0.08 W cm−2), the device exhibits a ≈4.50% (≈13.9 F g−1) increase in capacitance after each charging‐discharging cycle. The study provides a guideline for designing multi‐functional supercapacitors that serve as both the energy supplier and the photo‐detector. [ABSTRACT FROM AUTHOR]

In recent years, new carbonized nanomaterials have emerged in imaging, sensing, and various biomedical applications. Published literature shows that carbon dots (CDs) have been explored more extensively than any other nanomaterials. However, its polymeric version, carbon polymer dots (CPDs), did not get much attention. The non-conjugated and single-particle CPDs have all the merits of polymer and CDs, such as photoluminescent properties. The partially carbonized CPDs can be applied like CDs without surface passivation and functionalization. This merit can be further enhanced through the selection of desired precursors and control of carbonization synthesis. CPDs can absorb UV-visible-NIR light and can enhance the photoresponsive chemical and biochemical interactions. This review aims to introduce this area of renewed interest and provide insights into current developments of CPDs nanoparticles and present an overview of chemical, biological, and therapeutic applications.

This study presents the fabrication of Mg x Zn (100-X) O thin films (TFs) with Mg concentration levels (x) of 0.5 at%, 1.0 at%, 1.5 at%, and 2.0 at% on glass substrates using the novel laser-assisted chemical bath growth (LACBG) method, aimed at investigating their photo-response for potential UV photodetector applications. Utilizing a continuous wave semiconductor laser with a 444.5 nm wavelength, 1 W power, and 6 min of irradiation, the LACBG method successfully produced high-quality Mg-doped ZnO TFs. These films were deposited on glass substrates coated with silver (Ag) to serve as electrode contacts for constructing a metal-semiconductor-metal (MSM) UV photodetector. The structural, optical, and electrical properties of the TFs were thoroughly analyzed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to examine the crystal microstructures and surface morphologies, revealing vertically aligned hexagonal symmetrical sub-micro tubes. In contrast, energy dispersive X-ray (EDX) analysis confirmed successful Mg incorporation into the ZnO lattice. UV–visible absorbance spectra indicated a blue shift in the absorption edge and increased band gap energy from 3.24 eV to 3.67 eV with rising Mg content. The UV photodetectors, particularly those with 2.0 at% Mg-doped ZnO TFs, demonstrated significantly enhanced UV responsiveness attributed to optical confinement, high surface-to-volume ratio, and superior structural quality. Performance metrics for the 2.0 at% Mg-doped ZnO TFs included a responsivity of 10.60 A/W, external quantum efficiency of 34.10, specific detectivity of 2.25 × 107 Jones, noise equivalent power of 5.34 × 10−11 W, rise time of 86.9 ms, and decay time of 324.4 ms. These findings underscore the potential of Mg-doped ZnO TFs for high-performance UV photodetection applications. The novelty of this study lies in utilizing LACBG to achieve high-quality Mg-doped ZnO TFs, offering a cost-effective, low-temperature method that enhances UV photodetector performance. [Display omitted] • Developed Mg-doped ZnO nanotube films using a laser-assisted chemical bath growth (LACBG) method. • Analyzed the effects of Mg doping levels (0.5–2.0 at%) on structural, optical, and electrical properties. • Observed a blue shift in absorption edge and increased band gap energy from 3.24 eV to 3.67 eV with higher Mg content. • Achieved significant UV photodetector performance with 2.0 at% Mg-doped ZnO TFs, showing a responsivity of 10.60 A/W. • Demonstrated detectivity of 2.25×107 Jones and low noise (5.34×10−11 W), showing potential for advanced UV photodetection [ABSTRACT FROM AUTHOR]

Abstract Stimuli‐responsive supercapacitors have attracted broad interest in constructing self‐powered smart devices. However, due to the demand for high cyclic stability, supercapacitors usually utilize stable or inert electrode materials, which are difficult to exhibit dynamic or stimuli‐responsive behavior. Herein, this issue is addressed by designing a MoS2@carbon core‐shell structure with ultrathin MoS2 nanosheets incorporated in the carbon matrix. In the three‐electrode system, MoS2@carbon delivers a specific capacitance of 1302 F g−1 at a current density of 1.0 A g−1 and shows a 90% capacitance retention after 10 000 charging‐discharging cycles. The MoS2@carbon‐based asymmetric supercapacitor displays an energy density of 75.1 Wh kg−1 at the power density of 900 W kg−1. Because the photo‐generated electrons can efficiently migrate from MoS2 nanosheets to the carbon matrix, the assembled photo‐responsive supercapacitor can answer the stimulation of ultraviolet‐visible‐near infrared illumination by increasing the capacitance. Particularly, under the stimulation of UV light (365 nm, 0.08 W cm−2), the device exhibits a ≈4.50% (≈13.9 F g−1) increase in capacitance after each charging‐discharging cycle. The study provides a guideline for designing multi‐functional supercapacitors that serve as both the energy supplier and the photo‐detector.

Stepwise assembly starting from a preassembled metalloligand is a promising approach to obtain otherwise unattainable silver nanoclusters, but hard to be intrinsically identified due to the lack of convincing evidence to justify such a process. Herein, hexagonal and rectangular Ag18 nanoclusters are constructed from the [Mo2O5(PTC4A)2]6− (H4PTC4A=p‐phenyl‐thiacalix[4]arene) metalloligand through stepwise assembly. The formation of the metalloligand is confirmed by electrospray ionization mass spectrometry, then assembled with silver ions to form two geometrically different Ag18 nanoclusters in different solvents. The cyclization from the metalloligand to [(Mo2O5PTC4A)6]12− can be realized without alcohols and otherwise blocked by them. The installation of this metalloligand not only provides comprehensive understanding of how the solvents regulate the silver nanocluster structures, but also brings new insights for the controllable ligand metallization and subsequent condensation. [ABSTRACT FROM AUTHOR]

The realm of titanium coordination polymer research is still in its nascent stages and presents a formidable challenge in the field of coordination chemistry. In recent decades, the focus has predominantly been on manipulating titanium reactions in solution, resulting in the synthesis of ≈60 targeted compounds. Despite the limited number of documented instances, these materials showcase a diverse array of structures, encompassing 1D chains, 2D layers, and 3D frameworks. This suggests potential for fine-tuning coordination modes and structural features in future investigations. Moreover, titanium coordination polymers not only exhibit photo-active and photo-responsive properties but also hold promise for various other significant applications. This article offers an exhaustive review tracing the evolution of titanium coordination polymer development while providing an update on recent advancements. The review encompasses a synopsis of reported synthetic strategies, methodologies, structural diversity, and associated applications. Additionally, it delves into critical issues that necessitate attention for future progressions and proposes potential avenues to effectively propel this research field forward at an accelerated pace., (© 2024 Wiley‐VCH GmbH.)

Magnetotactic bacteria (MTB) synthesize intracellular magnetic organelles, magnetosomes, which consist of magnetic crystals that are enveloped in a membrane. Magnetosomes are organized into a chain(s) and confer on cells a magnetic dipolar moment. This magnetic property allows MTB cells to align and swim along geomagnetic field lines, a movement referred to as magnetotaxis. Some MTB species change their swim direction in response to illumination by UV, violet and blue light. Here we analyzed the polarity of morphology, magnetism, and motion in Mediterranean multicellular magnetotactic prokaryotes, also called, magnetoglobules or MMP. The magnetoglobules were assembled from 60–80 cells into an asymmetric ellipsoidal morphology with a relative narrow and large end. They swam dominantly northward, parallel to the direction of the magnetic field, with the narrow-end as the leading side. In response to a reversal in the direction of the magnetic field, they aligned quickly along the magnetic field lines and kept swimming northward. Interestingly, under constant illumination, 385-nm UV light, magnetoglobules changed their swimming direction southward anti-parallel to the direction of the magnetic field, with the large-end as the leading side. The change from a northward to southward direction occurred along with an increase of swimming speed. A minimum of 35-mW/cm2 irradiance of UV light was sufficient to trigger the swimming re-orientation. UV radiation also triggered the unidirectional division of magnetoglobules. Together these results revealed a coordination of the polarity of magnetoglobule morphology, magnetic moment, and swimming orientation, in response to magnetic and optical stimuli. The UV triggered the reversal of magnetotaxis and magnetoglobule division indicating the ecological significance of light for multicellular magnetotactic prokaryotes. [ABSTRACT FROM AUTHOR]

Solid-stated smart polymers responsive to external stimuli have attracted much attention for potential application in the field of photoelectron devices, logic gates, sensor, data storage and security. However, it is a bigger challenge for polymers than that for small molecules in solid state to acquire stimuli-responsive properties, because polymers with high molecular weight are not as easy to change the packing structure as small molecules under external stimulation. Here, a D-A type alternating copolymer PTMF-o containing 3,4-bisthienylmaleimide (A unit) and fluorene (D unit) is designed and synthesized. Upon irradiation of sunlight, PTMF-o film exhibits a photo-response with the color altering from purple to colorless. It is attributed to the structure of copolymer transformed from ring-opening form (PTMF-o) to ring-closure form (PTMF-c), resulting from the oxidative photocyclization of 3,4-bisthienylmaleimide unit. Consequently, the ability of charge transfer (CT) from fluorene to 3,4-bisthienylmaleimide unit in PTMF-o can be easily weakened by light stimuli. PTMF-o film displays a WORM-type resistive storage performance for the strong CT. Interestingly, after exposure, the electrical memory behavior in situ transfers into FLASH type, due to weak CT in PTMF-c. PTMF-o film can also be employed as smart material to construct NAND and NOR logic gates by using light as input condition. The work provides a simple way to modify the electronic properties of polymers and realize stimuli-response in solid states. [ABSTRACT FROM AUTHOR]

• POPs functionalized by Azo and phosphonium units were fabricated for organic dyes removal. • Azo-POP exhibits extraordinary adsorption capacity towards anion dyes. • The removal efficiency of Congo Red (CR) could reach 100 % in 30 s. • The adsorption capacity of Azo-POP is photo-tunable. Adsorption has been recognized as a highly economical and feasible technique for the removal of organic pollutants from water. Thus, the search for novel and efficient porous adsorbents for water purification is a crucial and pressing task. Here, a new family of azobenzene- and phosphonium-functionalized porous organic polymers (Azo-POPs) were fabricated via a post-synthesis approach. By taking advantage of the photo-tunable transformation of Azo units, the adsorption behaviors of two isomers of Azo-POP, trans- Azo-POP and cis- Azo-POP, were examined. The results demonstrated that both of Azo-POPs exhibited extraordinary adsorption capacity and adsorption rate towards anionic dyes due to their porous structure, cation-charged and hydrophilic skeleton. However cis- Azo-POP afforded much more efficient adsorption performances. The removal efficiency of Congo red (CR) could reach 100 % in 30 s, and the maximum adsorption capacity was as high as 1376.8 mg g−1, surpassing most previously reported adsorbents. The pseudo-second-order rate constant of cis- Azo-POP was 16.9153 g mg−1min−1. Additionally, Azo-POP adsorbents could be easily regenerated and reused over five cycles without any loss of adsorption capability. Therefore, the study suggests a universal platform for the fabrication of functional POP materials, which will find great potential in the fields of industrial wastewater treatment and catalysis. [ABSTRACT FROM AUTHOR]

Enclosing the pesticide in a carrier and releasing it based on environmental stimuli is proved to be a viable strategy for addressing pesticide losses and mitigating environmental contamination. Here, an interpenetrating network (IPN) composite hydrogels (OMt/Alg/PNIPAm) with light and temperature responses was prepared by the incorporation of clay material, organo-montmorillonite (OMt), via the free-radical polymerization of N-isopropyl acrylamide (PNIPAm) and its crosslinking as well as ionic crosslinking reaction of sodium alginate (SA) with FeCl 3. The structure of OMt/Alg/PNIPAm was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermos gravimetric analysis (TGA) and rheometer. The hydrophobic pesticide λ-cyhalothrin (LC) was encapsulated in OMt and subsequently incorporated into the IPN structure of the composite hydrogels, ensuring the desirable mechanical properties, encapsulation efficiency and sustained release performances of the composite hydrogels. In addition, with the rising of OMt content, the IPN composite hydrogels exhibited a decrease in their swelling capacity, transparency, and temperature sensitivity. The OMt/Alg/PNIPAm with 9.0% OMt content displayed the highest loading rate for pesticides at 82.06% and the lowest release rate of pesticides at 3.90%. Furthermore, the IPN composite hydrogels possessed the ability to regulate the amount of pesticide release based on the variations in temperature and ambient light conditions. The resultant IPN composite hydrogels took advantage of the temperature responsiveness of PNIPAm, the light sensitivity of Fe3+-alginate hydrogel, and the adsorption capability of OMt, possessing great potentials in enhancing the utilization efficiency of hydrophobic pesticides through the development of effective and eco-friendly pesticide formulations. [Display omitted] • The intelligent OMt/Alg/PNIPAm with light and temperature response were prepared via IPN method. • The chemical crosslinking of PNIPAm and ionic crosslinking of SA achieved IPN composite hydrogels. • OMt was used to improve the mechanical property and drug-loading rate of the OMt/Alg/PNIPAm. • The OMt/Alg/PNIPAm could regulate the pesticide release in response to environmental stimuli. • The OMt/Alg/PNIPAm could be preferably used as potential hydrophobic pesticide carriers. [ABSTRACT FROM AUTHOR]

Quaternary (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals, pivotal for advanced sensing applications, were successfully grown utilizing the direct vapour transport (DVT) technique. An integrated approach, encompassing scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX), explored the morphological and chemical composition of the as-grown crystals. The resulting hexagonal structure was confirmed via X-ray diffraction (XRD), while the Williamson–Hall model revealed a crystallite size and lattice strain. Impressively, the crystals exhibited a direct band gap of 1.03 eV. Comprehensive kinetic insights were gleaned from differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) curves, enhancing our understanding of the material's thermal behaviour. Electrical resistance studies, conducted as a function of temperature and vacuum pressure, underscored the intricate interplay between these parameters and the crystal's conductivity. Remarkable photo-response properties were meticulously evaluated under varying illumination intensities, showcasing crystals potential in photo-sensing applications. The crystal's exceptional capabilities extended to the realm of human respiration monitoring, where it facilitated the measurement of electrical currents across diverse breathing conditions. Photo-catalytic process was harnessed for environmental remediation, particularly for the degradation of methylene blue (MB) under visible light irradiation. Collectively, these findings position the (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals as a compelling contender for versatile multi-sensing devices. • Sucessful Growth of (Ge 0.03 In 0.97)(Se 0.95 S 0.05) using direct vapour transport (DVT) technique. • The grown crystals were characterized through extensive characterization. • Study involves the photo-catalytic properties of the (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals under visible light irradiation. • Investigation on Thermal stability of grown crystals by the TGA and DSC curves. • (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals unique combination of properties, including high sensitivity and visible-light responsivity. [ABSTRACT FROM AUTHOR]

Photo-responsive mechanical actuator is a class of stimuli-responsive materials transferring light to mechanical energy through macroscopic transformation. To fabricate photo-responsive mechanical actuator, soft polymeric materials crosslinked with functional bridging structures are desired. Supramolecular interaction is a relatively common way to fabricate crosslinked materials due to its excellent self-assembly performance. And azobenzene and derivatives are ideal candidates of photo-responsive materials because of the unique photo-induced trans-cis isomerization. Here, a new kind of crosslinked materials based on supramolecular interaction between 4,4′-dihydroxyazobenzene and chitosan is reported. Under 355 nm irradiation, the macroscopic bending of polymeric materials occurs rapidly due to the photo-isomerization of 4,4′-dihydroxyazobenzene. Meanwhile, the photo-responsive mechanical actuator can also lift weight which is up to 200 times that of the actuator itself, and convert energy from light to mechanical work efficiently. This report suggests a new kind of photo-responsive actuator based on supramolecular interaction and may be helpful to contribute a theoretical basis to the design and synthesis of photo-responsive mechanical actuator suitable for large-scale manufacturing industrialization in future. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive fluorescent materials with aggregation‐induced emission (AIE) characteristics have attracted increasing attention owing to their advantages of bright fluorescence in the solid state and the ability to tune the structures and physicochemical performances in response to various stimuli. Among all the available external stimuli, light stands out, and has rapidly become a focus of research, because it offers green and remote triggering, noninvasive manipulation, high spatiotemporal resolution, and convenient tunable properties. Consequently, photo‐responsive AIE materials provide a fascinating strategy for constructing functional fluorescent materials. This review summarizes the recent advances in the fabrication of photo‐responsive fluorescent materials with AIE characteristics by grafting AIE fluorogens (AIEgens) into photochromic molecules. State‐of‐the‐art photo‐responsive AIE materials based on the inherent photochemical reactions of AIEgens are highlighted, and are classified and discussed according to the photochemical pathways, including photocyclization, photo‐isomerization, photodimerization, photo‐removal, and multiple photoreactions. Following this, the corresponding applications of photo‐responsive AIE materials in bio‐imaging, anti‐counterfeiting, photo‐patterning, photo‐release of chemicals or drugs, and photo‐controlled assembly and disassembly are introduced. Finally, the most promising directions for development and applications of photo‐responsive AIE materials are outlined and discussed. [ABSTRACT FROM AUTHOR]

A reversible photo-, thermal-, and pH-responsive high-performance functional wood with fluorescence has been prepared. The properties, structure, multi-response, fluorescence, water resistance, and corrosion resistance of original wood (ORW) and functional wood (FUW) were investigated with an X-ray photoelectron spectroscopy (XPS) spectrometer, a Fourier-transform infrared (FTIR) spectrometer, a N2 adsorption–desorption analyzer, an atomic force microscope (AFM), tensile tests, a scanning electron microscope (SEM), an ultraviolet–visible (UV–Vis) spectrophotometer, a fluorescence spectrometer, the equilibrium swelling ratio (ESR), and corrosion tests. The results of XPS, FTIR, N2 adsorption–desorption, and AFM exhibited that FUW was successfully prepared. Additionally, the results of the tensile test and SEM revealed that FUW had better mechanical properties than ORW, due to the filling of epoxy resin in the pores of the wood. Moreover, the UV–Vis and fluorescence spectra demonstrated that the introduction of epoxy resin induced multi-response and fluorescence functions to FUW. Furthermore, the data of ESR and corrosion test showed that the introduction of epoxy resin greatly improved the water and corrosion resistance of wood. This study provides ideas and methods for preparing novel high-performance multi-response FUW.

We report an investigation on the photo-response from a GeSn-based photodetector using a tunable laser with a range of incident light power. An exponential increase in photocurrent and an exponential decay of responsivity with increase in incident optical power intensity were observed at higher optical power range. Time-resolved measurement provided evidence that indicated monomolecular and bimolecular recombination mechanisms for the photo-generated carriers for different incident optical power intensities. This investigation establishes the appropriate range of optical power intensity for GeSn-based photodetector operation.

Cubic perovskite oxides are attracting wide attention for applications in electronics and optoelectronics due to their high electronic mobility, however, realization of p -type conductivity in these oxides is still a matter. Barium stannate (BaSnO 3) is one of such materials, wherein low-amount of lanthanum-doping can induce an extremely high room-temperature electron mobility. In this work, anion-doping strategy was explored to realize the p -type conductivity in BaSnO 3 , and the underlying physics of transport was investigated. It is found that nitrogen substitution for oxygen can induce the p -type conductivity in BaSnO 3 thin films. By analyzing the temperature-dependent resistance and negative magnetoresistance data, Efros-Shklovskii variable-range hopping conduction is identified as the dominant transport mechanism in p -type BaSnO 3 thin films. Additionally, nitrogen-doped BaSnO 3 homojunctions exhibit good rectifying and photo-response properties. This study provides an alternative strategy for realizing the p -type conductivity in stannate-based perovskite oxides, and is helpful for designing the properties of stannate-based devices. [ABSTRACT FROM AUTHOR]

This work aims to study the photo-response of the fabricated silicon-based Al/PVP:ZnTiO 3 /p-Si photodiode (PD) in a wide range of illumination intensities. To make a metal-polymer/nanocomposite-semiconductor (MPS) PD, a thin film of PVP:ZnTiO 3 nanocomposite is deposited at the interface of the metal-semiconductor (MS) structure. Information regarding the preparation and manufacturing procedures is provided. Through the examination of the current-voltage (I–V) behavior, essential electrical properties such as leakage current (I 0), barrier height (Φ B0), ideality factor (n), series and shunt resistances (R s , R sh), energy-dependent interface states density (N ss), photocurrent (I ph), and photosensitivity (S) are acquired. The thermionic emission (TE) theory, along with the Norde and Cheung methods, is employed to calculate the parameters Φ B0 , n, and Rs. The values of Φ B0 and R s are decreased by raising the illumination intensity while the n value is increased. In addition, the illumination coefficient (α) and the value of Φ B0 in the ideal case are determined from the Φ B0 -P and Φ B0 -n plots. The efficiency (η) of the sample is calculated at each illumination intensity whose maximum value is 2.30 % at the intensity of 450 mW/cm2. The illumination-dependent photocurrent is investigated at the negative bias region that shows a good linear behavior in the ln(I ph)-ln(P) profile. The photosensitivity (S) of the fabricated PD is obtained as ⁓500 which is, compared with previous PDs. These findings demonstrate that the developed silicon-based MPS-type PD with a structure of Al/PVP:ZnTiO 3 /p-Si exhibits a good photo-response and can successfully replace traditional MS PDs in optoelectronic and photovoltaic applications. • A Si-based Schottky photodiode (PD) with a PVP:ZnTiO 3 interlayer is introduced. • The opto-electric response of the fabricated PD is measured under illumination. • The interface states density in the PD is reduced under illumination. • The efficiency of the PD is maximized at the illumination intensity of 450 mW/cm2. • The photosensitivity of the PD is higher than others introduced in literature. [ABSTRACT FROM AUTHOR]

Hybrid halide perovskites have emerged as pivotal optoelectronic materials due to their easy and cost-effective solution-based manufacturing processes. In this study, we have combined formamidinium lead bromide (FAPbBr 3) with buckminsterfullerene (C 60) to create the bulk heterojunction (BHJ) photoactive layer for solution-processed photodetectors. Remarkably, the FAPbBr 3 :C 60 BHJ-based photodetectors exhibited a substantial enhancement in optoelectronic performance, with the responsivity increasing from 0.87 A/W to 1.47 A/W compared to the pristine FAPbBr 3. This improvement can be attributed to the superior surface morphology and crystallinity of the FAPbBr 3 :C 60 BHJ thin film, which facilitated enhanced charge transport properties. Furthermore, the fabricated photodetectors demonstrated remarkable detectivity even at 0V, enabling self-powered operation. By employing the space charge limited conduction (SCLC) model, we were able to elucidate the dominant charge transport mechanism. At lower voltages, trap-free SCLC was identified as the primary mechanism, while traps governed charge transport at higher voltages. Additionally, we conducted impedance analysis to investigate the underlying factors contributing to the distinctive optoelectronic performance observed in the photodetectors. • Blended FAPbBr 3 with C60 to create the BHJ photoactive layer. • BHJ-based photodetectors exhibited a superior performance than pristine FAPbBr 3. • The PDs showed remarkable detectivity even at 0V, enabling self-powered operation. • Studied dominant charge transport mechanism in the devices. [ABSTRACT FROM AUTHOR]

Abstract The feather-like hierarchical zinc oxide (ZnO) was synthesized via successive ionic layer adsorption and reaction without any seed layer or metal catalyst. A possible growth mechanism is proposed to explain the forming process of ZnO feather-like structures. Meanwhile, the photo-electronic performances of the feather-like ZnO have been investigated with the UV-vis-NIR spectroscopy, I-V and I-tmeasurements. The results indicate that feather-like ZnO hierarchical structures have good anti-reflection and excellent photo-sensitivity. All results suggest that the direct growth processing of novel feather-like ZnO is envisaged to have promising application in the field of photo-detector devices.

Increasing the carrier concentration as well as carrier life time could be effective ways to increase the photoresponse of a photoconductive type photodetector. In this paper, layer-structure photodetectors have been fabricated by connecting CH 3 NH 3 PbI 3 film with and without electron transport layer (SnO 2 and SnO 2 /PCBM bilayer). We found that the electron extraction at the electron transport layer and MAPbI 3 interface will boost the photocurrent and responsivity, and faster electron extraction will result in a higher photocurrent improvement. At the same time, the closer is the distance of the interface to the photogenerated electron-hole pairs, the larger is the photocurrent enhancement. The largest photocurrent increasement is almost 3 times the initial value, which increases from 1.54 μA to 6.10 μA. Image 1 • Electron extraction from excited active layer boosts the photo-response of Au/CH 3 NH 3 PbI 3 /Au photodetector. • Higher electron extraction velocity, higher improvement in photo-response. • The closer is the photon generated electron and electron extraction layer, the higher is increasement in photocurrent. [ABSTRACT FROM AUTHOR]

Lead sulfide (PbS)/manganese sulfide (MnS) heterojunction is synthesized by a simple two-step chemical bath deposition technique. The as-synthesized heterojunction is studied based on the optical and electrical analyses. The optical absorbance spectrum of the test structure confirms dual peaks at two different wavelengths, which has prompted consideration of the two band gaps of the structure. The origin of dual peaks in the absorbance plot is attributed to the existence of the PbS base layer and the MnS window layer. The band gaps are estimated using the conventional Tauc's method (Eg = 1.75 eV and 2.9 eV) and also by the absorbance spectrum fitting method (Eg = 1.82 eV and 2.97 eV). In the dc analyses, the PbS/MnS heterojunction possesses low dark current and high dynamic resistance. However, under illumination (400-700 nm) a distinct photo-response is observed, showing a substantial rise in device current with the reduction of dynamic resistance. The photo-response of the heterojunction is examined at 635-699 nm, 514-538 nm and 410-452 nm wavelengths by analyzing the photo-current and photo-resistance. The device is found to be more photosensitive at lower wavelength illuminations compared to the higher wavelength exposures. [ABSTRACT FROM AUTHOR]

Highlights • The p-ZnTe/n-CdS heterojunction photodetectors were fabricated. • New technique of nanoparticle incorporation was used to dope ZnTe with bismuth. • The photocurrent increased nearly 10 times after doping. • The spectral response curve became sharper after doping. • The response time of the device became faster after doping. Abstract The effect of bismuth nanoparticle incorporation on the characteristics of p-ZnTe/n-CdS light sensors is evaluated in detail. The device was fabricated by vacuum evaporation method. The bismuth nanoparticles were obtained on the substrates kept at 453 K. The electrical conductivity of ZnTe layer was found to increase significantly after the introduction of bismuth nanoparticles. The I-V and C-V characteristics of the devices showed significant improvement in the electrical characteristics after doping. The photo-response properties of the diodes was also found to improve after the incorporation of bismuth. The photocurrent increased nearly 10 times and the photo-response was found to be much faster. [ABSTRACT FROM AUTHOR]

Photo-induced multi-color fluorescent hydrogels based on CPMC, SPCOOH and DCF for optical information encryption and coding. [Display omitted] • We fabricate multi-color fluorescent hydrogels containing CPMC, SPCOOH and DCF. • Hydrogels prove various photo-response induced by light of different band. • Based on the effect of borax, hydrogels possess reversible cross-linking property. • We apply the hydrogels to optical information coding and encryption. In this study, we proposed a method to prepare multi-color fluorescent hydrogels with polyvinyl alcohol (PVA) as the cross-linking network and 7-(6-carboxylpentoxy)-4-methylcoumarin (CPMC), N-ethoxyhexanoate-3,3-dimethyl-6-nitro-indolinspiropyran (SPCOOH) and 2′,7′-dichlorofluorescein (DCF) were introduced to the system. Due to the hydroxyl group in PVA can form a reversible borate bond with borax, the hydrogel could be combined with each other through this chemical bond, thus hydrogels possess reversible cross-linking property and programmable property. The introduction of CPMC, SPCOOH and DCF into the hydrogel could give the hydrogel different photo-response properties. Under UV light irradiation, PVA-CPMC, PVA-CPMC/DCF, PVA-SPCOOH and PVA/DCF hydrogels could emit blue, cyan, pink purple and green fluorescence respectively. In addition, PVA/DCF and PVA-CPMC/DCF hydrogels could emit green fluorescence under 505 nm light irradiation. Based on the various properties of hydrogels, we respectively demonstrated the application of hydrogels in the fields of two-dimensional information encryption, three-dimensional information encryption, three-dimensional information coding and anti-counterfeiting, which can achieve the expected results. Therefore, multi-color fluorescent hydrogels may have potential applications in information encryption, information coding, flexible display and other fields. [ABSTRACT FROM AUTHOR]

A highly hydrophobic porphyrin: di-octadecyl-amide deuteroporphyrin (D-ODA) was synthesized and incorporated into liposomes (Lipo-D-ODA) through self-assembling of the aliphatic chains. From the fluorescence spectra, it was concluded that the long alkyl carboxylate chains accommodate the sensitizer into the lipid bilayer, is less exposed to quenching induced by aggregation. The light excited liposome Lipo-D*-ODA activated the ground state molecular oxygen to produce oxygen singlet or superoxide anion. The electrochemical responses of two structurally different redox-active analytes were studied. Quercetin oxidation at 200 mV was only observed after irradiation on the Lipo-D-ODA/Quercetin, indicating that it is embedded in the liposome and requires membrane rupture. On the contrary, the signal of Ferrocene-ODA was independent of irradiation because the redox polar moieties (Ferrocene) were oriented in aqueous space. [ABSTRACT FROM AUTHOR]

There is growing interest in "more-than-human" influences on places and practices. However, while the theoretical thinking in this field is well developed, methodology and methods lag behind. Borrowing insights from feminist geographers' articulation of "response", we explore how participatory photography can be used to examine more-than-human processes through a case study of marginal homemaking in Khulna city in Bangladesh. Our photo-response method focuses on performances of seeing, telling and being together to enhance the co-production of "knowledges". We conclude that analysing three stages of "response" within participatory photography provides new insights for conducting research in, with and as more-than-human worlds. [ABSTRACT FROM AUTHOR]