Photosensitive Devices Research Articles

Graphene Oxide-Doped Indium Oxide Buffer Film Sandwiched between Titanium Oxide Layers for the Development of Photosensitive Resistive Memory Devices.

Over the past decade, metal oxide semiconductors have attracted considerable attention because of their transparency, high intrinsic charge carrier mobility, and charge carrier density. Metal oxide semiconductors also provide a promising route to develop resistive memory devices because of the tunability of their conductivity via the removal of oxygen ions, forming oxygen vacancies that can act as electron donors. Here, this paper reports the fabrication of a resistive random-access memory (ReRAM) device with TiO2 and TiO2-x layers and introduces a solution-processed In2O3-graphene oxide (GO) buffer layer from a water-based precursor solution to tune the switching characteristics. The devices were compared with a ReRAM device with no buffer layer, and the device composition was optimized by tuning the GO concentration in the layers. The devices showed hysteresis under cyclically scanned bias between positive and negative voltages with clear switching between the low resistance state (LRS) and the high resistance state (HRS). The optimized device also showed a more than 3 orders of magnitude difference in resistance between the LRS and HRS and a stable current retention. The devices also showed photoresponsive behaviors. In the LRS, the current increased significantly under illumination, while in the HRS, the current deteriorated slowly when constantly illuminated. These results highlight the dual role of the GO flakes in the buffer layer by increasing the resistance in the HRS and providing a photoresponsive switching capability. The ReRAM device was connected to a TFT device, and its feasibility as a memory component in a digital circuit was successfully demonstrated. These results provide a new avenue for developing metal-oxide-based ReRAM devices with GO-containing active layers.

First‐Principle Investigation of zb‐TiGe: A Promising Narrow Bandgap Semiconductor

Using first‐principle calculations, a new compound semiconductor based on titanium (Ti) is predicted. It has been observed that Ti when alloyed with germanium (Ge) can crystallize in the zincblende symmetry, and exhibits semiconducting nature with a narrow bandgap. To test the robustness of the semiconducting nature, the structural properties and electronic band structure have been modeled using three different exchange–correlation functionals, namely, local density approximation, generalized gradient approximation, and Perdew‐Burke‐Ernzerhof for solids. With a nominal composition of 1:1, TiGe exhibits a direct bandgap of 0.58 eV at the “X” point of the Brillouin zone. From lattice dynamics, the structural stability of the compound has been established. The new semiconductor is characterized in detail for its electronic band structure, carrier effective mass, charge density distribution, and linear optical properties. Zb‐TiGe exhibits large effective mass for conduction band holes and tentatively becomes a prototype system to study heavy holes resulting in carrier condensation at the bottom of the conduction band. The linear optical properties of the TiGe are found to be suitable for photosensitive devices in the infrared region. In addition, TiGe may find application in deep‐UV and far‐UV regions because of the surface plasmon resonance at 6.4 eV.

Optimizing optoelectronics performance: theoretical and experimental study on ZnO thin film for Al/ZnO/p-Si photodiode

Abstract In this paper, a ZnO photodiode in a p-n heterojunction configuration is fabricated on a p-type Si substrate focusing specifically on ZnO/p-Si heterojunction photosensitive devices and photodiodes (PDs) using Al contacts. Through an experimental and theoretical analysis approach aims to evaluate the effects of important parameters, including ZnO layer thickness, defect density, and contact materials, on PD’s efficiency. Numerical analysis simulations comparatively examine the experimentally fabricated device performance at a 5 nm ZnO layer thickness by balancing photon absorption and carrier formation while minimizing carrier transport limitations. Experimentally process, an Atomic Layer Deposition (ALD) system was used to grow ZnO interlayers on one side of the polished Si wafer. Then, Al metallic contacts were created on the ZnO layers using a hole array mask. The PDs were then subjected to electrical characterization using I-V and I-t measurements under various illumination densities. Al/ZnO/p-Si PD’s device with active performance has been produced and analyzed with electrical parameters such as barrier height, photocurrent, spectral response, ideality factor and EQE were derived, analyzed and studied. In conclusion, this work provides a comprehensive understanding of the performance of Al/ZnO/p-Si PD at varying illumination intensities and offering a detailed analysis of key parameters influencing device efficiency for future optoelectronics applications.

Fabrication of bacteriorhodopsin-embedded hydrogel construct for biocompatible photosensitive device

Bacteriorhodopsin (br) is a promising photosensitive material with applications in energy conversion, biosensors, and optoelectronic devices due to its bio-sourced origin and photoelectrical properties. Despite advancements in recent years, the integration of br-based devices necessitates the use of materials with little biocompatibility and fabrication techniques with restricted customizability, limiting potential applications such as optocontrol of cell behavior, implants with 3D patterning for retinal disease treatment, and light-sensitive cell robots. To solve this limitation, this study presents a novel approach by embedding br into a hydrogel matrix. It utilizes an extrusion-based and 3D bioprinting technique, showcasing its light-sensitive characteristics within a fully biocompatible construct. The hydrogel, comprising gelatin and sodium alginate, offers excellent printability for generating structured designs with versatile patterns. Photoelectrical properties of the fabricated br-embedded hydrogel construct, such as differential response, light intensity sensitivity, and br concentration sensitivity, are identified through electrochemical characterization. The temporal and spatial pattern recognition ability, based on the photoelectrical characteristics, is demonstrated through modulated light illumination and different patterns of printed hydrogel construct. Pattern recognition ability was then applied to reconstruct images containing different Latin letters. This research presents a novel method for the fabrication of patterned hydrogel constructs with high biocompatibility and distinctive light-responsive properties, expanding the potential applications of br in bio-related scenarios.  

Upconversion-nanoparticle-assisting near-infrared photosensitive effect at 1550 nm in organic photorefractive devices

The near-infrared (NIR) photosensitive photorefractive device is a promising optoelectronic unit in the optical signal/information processing and telecommunication. In this work, the upconversion-assisting NIR photosensitive device is presented by adding the upconversion nanoparticles (UCNPs) to the photorefractive composite with (Vlieg et al., 2022; Vlieg et al., 2022) [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as visible photosensitizer. The XRD and TEM results indicated the hexagonal β-phase nanoparticles of UCNPs. The PL measurement under the 1550-nm excitation showed the upconversion emission peaks of NaYF4:Er@NaYF4 nanocrystals at the visible lights of 525 nm, 545 nm and 650 nm. The SEM images revealed that the CRA-DR1 photorefractive composite takes on a good morphology due to the uniform distribution of UCNPs. The two-beam coupling (TBC) experiment without external electric filed indicated the coupling gain coefficient of 77.4 cm−1 at 1550 nm in the CRA-DR1/ECZ/PC61BM/(5 %)UCNPs composite. This upconversion-assisting photosensitive effect will open up the novel approaches for organic NIR photorefractive devices.

Computational Investigation of Structural, Electronic and Optical Properties of Ternary Chalcogenide TLGaQ2 Monoclinic Compounds: a First Principle Study

Purpose: This paper aim to investigate and predict by simulation the impact of the substitution of Q-site atom (Q꞊S, Se) on the TIGaQ2 monoclinic compounds for the first time, along the three main polarizations of the incident wave directions [100], [010] and [001]. Theoretical Framework: This study focuses mainly on ternary chalcogenide compounds TlGaQ2 (Q= S, Se) from ABQ2 family to highlight the objective resources aimed at promising prospects offered for them. Design/Methodology/Approach: A series of ab-initio calculations based on the (PW+PP) method within the density functional theory DFT framework were carried out with CASTEP code for the simulation of their physical properties (structural, electronic-optical). The exchange correlation potential was treated within the generalized gradient approximation (GGA) implemented in the CASTEP code and expressed by the PBE functional. Findings: The equilibrium lattice parameters are in good agreement with the available experimental results. The calculated band structure shows that are direct bandgap semiconductor nature 1.92eV (1.41eV) for TlGaS2 and TlGaSe2 respectively with a great potential for photovoltaic solar cell absorber materials. A set of optical parameters were calculated including the complex dielectric function, the reflective index, reflectivity, the absorption coefficient and loss function. The optical properties obtained revealed very interesting optical properties exhibiting strong optical absorption in UV range up to (~2x105cm-1) for both compounds making them appropriate for photovoltaic solar-cell absorber materials. Furthermore, low reflectivity and energy loss function are shown within in the visible and ultraviolet energy range, allowing them to be promising materials in several optoelectronics applications likes photosensitive devices. Implications: All these findings results show a successful accurately prediction for chalcogenide materials behavior and will be helpful for future studies allowing a better understanding of their potential applications in modern photovoltaic technologies as well as within UV ranges for optoelectronics applications.

Wafer-Scale Growth and Transfer of High-Quality MoS2 Array by Interface Design for High-Stability Flexible Photosensitive Device.

Transition metal disulfide compounds (TMDCs) emerges as the promising candidate for new-generation flexible (opto-)electronic device fabrication. However, the harsh growth condition of TMDCs results in the necessity of using hard dielectric substrates, and thus the additional transfer process is essential but still challenging. Here, an efficient strategy for preparation and easy separation-transfer of high-uniform and quality-enhanced MoS2 via the precursor pre-annealing on the designed graphene inserting layer is demonstrated. Based on the novel strategy, it achieves the intact separation and transfer of a 2-inch MoS2 array onto the flexible resin. It reveals that the graphene inserting layer not only enhances MoS2 quality but also decreases interfacial adhesion for easy separation-transfer, which achieves a high yield of ≈99.83%. The theoretical calculations show that the chemical bonding formation at the growth interface has been eliminated by graphene. The separable graphene serves as a photocarrier transportation channel, making a largely enhanced responsivity up to 6.86mAW-1, and the photodetector array also qualifies for imaging featured with high contrast. The flexible device exhibits high bending stability, which preserves almost 100% of initial performance after 5000 cycles. The proposed novel TMDCs growth and separation-transfer strategy lightens their significance for advances in curved and wearable (opto-)electronic applications.

Characterization of the p-NiO/n-GaN heterojunction and development of ultraviolet photodiode

Nickel oxide semiconductor is a good p-type material for fabricating a p-n-heterojunction with n-type GaN semiconductor. The p-NiO/n-GaN heterojunction, which produces a type II band bias, has significant prospects for creating photosensitive devices. Herein, it is shown that a selective ultraviolet photodetector can be created based on this heterojunction. p-NiO films were formed using magnetron sputtering onto n-doped GaN epitaxial layers grown by plasma assisted molecular beam epitaxy. The structural, optical, and electronic properties of the formed nickel oxide films were studied. A mechanism for reducing dislocation density and conductivity and increasing transparency due to film annealing is proposed. It has been established that the current–voltage characteristics of the p-NiO/n-GaN heterojunction are typical for diode structures and show selective sensitivity to ultraviolet radiation. The band model and sensitivity of the fabricated ultraviolet photodiode were evaluated. The photosensitivity at zero voltage was 3.11 mA/W, the quantum yield was 0.011, and the detection ability was 8.69 × 109 Jones. The work shows the potential of using the p-NiO/n-GaN heterojunction to create ultraviolet photodetectors.

Contact Printed ZnO Nanowires-Based Flexible Photosensitive Devices for Large Area Smart Sensing

Contact Printed ZnO Nanowires-Based Flexible Photosensitive Devices for Large Area Smart Sensing

Investigations on the optical, dielectric, electrical, and rheological properties of PEG200/ZnO semiconducting nanofluids for soft matter based technological innovations

Semiconducting nanofluids (SNFs) consisting of poly (ethylene glycol) (PEG200) as a green biocompatible base fluid with homogeneous dispersion of eco-friendly zinc oxide (ZnO) nanomaterial, concentrations ranging from 0.01 to 0.20 wt%, are prepared by state-of-the-art ultrasonic cavitation homogenized process. These PEG200/ZnO SNFs are characterized by employing an ultraviolet-visible (UV-Vis) spectrophotometer, precision inductance-capacitance-resistance (LCR) meter, and rotational viscometer. A detailed analysis of 200–800 nm range UV–Vis absorbance spectra of these SNFs revealed longer stability of suspended ZnO nanoparticles in PEG200 fluid, and their nanomaterial concentrations dependent absorbance and extinction coefficient with tunable dual energy band gaps ranging from 3 to 5 eV. Optical performance recognized the potential applications of these SNFs in the advances of soft matter based optoelectronic and photosensitive devices and also as an excellent UV radiation shielding material. The study of 20 Hz – 1 MHz range dielectric and electrical spectra explained that the ZnO concentrations have a significant impact on the electrical conductivity of these SNFs, while the dielectric permittivity and electrode polarization relaxation process are marginally altered. High static dielectric permittivity (∼ 22) and low electrical conductivity of about μS/cm order, at 303.15 K, evidence the suitability of these SNFs in advances of energy storage devices. The rheological behaviour of PEG200/ZnO materials is carried out at different temperatures ranging from 303.15 to 323.15 K, which illustrates the Newtonian characteristics of these nanofluids with moderate dynamic viscosity and activation energy, and therefore, they could be utilized as effective heat transfer materials in photovoltaic/thermal devices and systems.

Synthesis, characterization, crystal structure, and fabrication of photosensitive Schottky device of a binuclear Cu(ii)-Salen complex: a DFT investigations.

This work explores one centrosymmetric binuclear Cu(ii)-Salen complex synthesis, characterization, photosensitive Schottky barrier diode (PSBD) function, and DFT spectrum. The crystal growth involves H2LSAL and Cu(NO3)2·3H2O in CH3OH + ACN (acetonitrile) solvent medium. Herein, structural characterization employs elemental, IR/Raman, NMR, UV-VIS, DRS, SEM-EDX, PXRD, SCXRD, and XPS analyses. The complex crystal size is 0.2 × 0.2 × 0.2, showing monoclinic space group C2/c. The dimeric unit contains two Cu(ii) centres with distorted square pyramidal (SQP) geometries. The crystal packing consists of weak C-H⋯O interactions. DFT and Hirshfeld surface (HS) further substantiated the packing interactions, providing valuable insights into the underlying mechanisms. The 2-D fingerprint plots showed the presence of N⋯H (3%) and O⋯H (8.2%) contacts in the molecular arrangement. NBO, QTAIM, ELF-LOL, and energy frameworks are utilized to investigate the bonding features of the complex. We extensively studied electrical conductivity and PSBD for H2LSAL and the complex based on band gap (3.09 and 3.07 eV). Like an SBD, the complex has better electrical conductivity, evidencing potentiality in optoelectronic device applications. Optical response enhances conductivity, according to I-V characteristics. Complex Schottky diode has lower barrier height, resistance, and higher conductivity under light. The complex transports charge carriers through space and is rationalized by the 'hopping process' and 'structure-activity-relationship' (SAR). The charge transport mechanism was analysed by estimating complex mobility (μeff), lifetime (τ), and diffusion length (LD). The experimental and theoretical DOS/PDOS plots provide evidence for the Schottky diode function of the complex.

Effect of Co-Doping on the Photoelectric Properties of the Novel Two-Dimensional Material Borophene

Borophene is a novel two-dimensional material with abundant crystal structure and photoelectric properties. We focus on the effect of co-doping on the electronic structure and optical properties of borophene using the first-principles method. The results show that the structure of Al and Ga co-doped borophene is obviously distorted because Al and Ga atoms have formed bonds with a bond length of 2.378 Å, and the two B atoms that bond together with Al and Ga are no longer formed bonds. However, it is also a two-dimensional planar structure after co-doping. After co-doping, the band gap width of the borophene system is narrowed from 1.409 eV to 1.376 eV, and the band gap is narrowed by 0.033 eV. Mulliken population analysis shows an obvious charge transfer between Al-B and Ga-B atoms in the co-doped borophene. The calculation of optical properties shows that the static dielectric constant ε1 (0) increases from 5.08 to 7.01, and ε2 (ω) is larger than that of the undoped sample in the low-energy range. Thus, the co-doping of Al and Ga can enhance the electromagnetic energy storage capacity and the visible light absorption ability. Although the reflectance of borophene is reduced by co-doping (the peak of the reflectivity can be decreased from 71% to 61% at E = 2.94 eV), it still presents metallic reflection characteristics. The static refractive index n0 can be increased from 2.25 to 2.65 by co-doping. The extinction coefficient shows strong band edge absorption at the low-energy range with an absorption edge of 0.85 eV. The light loss is limited to a very narrow energy range of approximately 7.30 eV, which indicates that borophene co-doped with Al and Ga can also be used as a light storage material. The optical conductivity reaches its maximum at E = 1.78 eV and 2.52 eV, which correspond to the light irradiation with a wavelength of 698 nm (red light) and 492 nm (cyan light), respectively. The results show that the Al-Ga co-doped borophene is sensitive to cyan light and red light, so it can be used to make photosensitive devices. The results can hopefully fill the gap in the application of borophene in semiconductor photoelectric devices and provide a theoretical basis for its application.

Deformation-controlled and ultrasensitive polyimide/paraffin wax/carbon nanotube composite NIR-responsive photoactuators

Light-responsive actuators have become increasingly popular in various fields such as soft robotics, biomedical devices, and photosensitive electronic devices due to their remote wireless operation and high deformation efficiency. However, controlling actuator deformation efficiency and modes remains a significant challenge. Herein, a new 3D printed polyimide (PI)/paraffin wax (PW)/carbon nanotube (CNT) NIR-responsive photoactuators with controlled deformation mode and ultrasensitive light response has been proposed. The process involves printing a CNT slurry according to a predetermined path, followed by lamination with PW and PI film to create PI/PW/CNT (PPC) NIR responsive photoactuators. Then, the effects of the CNTs pattern (line width and line spacing) on the deformation efficiency were studied and optimized. Upon optimization, the deformation time can be reduced to 3 s and the deformation angle can be raised to 70°. Moreover, the PPC actuator is highly sensitive to temperature and can be deformed within a temperature difference of about 2–3 °C. Finally, various PPC photoactuators including Flower-shape and soft mechanical hand have been prepared to present the different deformation forms. Overall, this work presents a new approach to researching multifunctional NIR-responsive photoactuators with adjustable deformation structures.

High-Performance Planar Field-Emission Photodetector of Monolayer Tungsten Disulfide with Microtips.

Monolayer tungsten disulfide (ML WS2 ) is believed as an ideal photosensitive material due to its small direct bandgap, large exciton/trion binding energy, high carrier mobility, and considerable quantum conversion efficiency. Compared with other photosensitive devices, planar field emission (FE)-type photodetectors with a full-plane structure should simultaneously have rapider switching speed and lower power consumption. In this work, ML WS2 microtips are fabricated by electron beam lithography (EBL) way and used to construct a planar FE-type photodetector. By optimization design, ML WS2 with three microtips can exhibit the maximum current density as high as 52 A cm-2 (@300V µm-1 ), and the largest photoresponsivity is up to 6.8 × 105 A W-1 under green light irradiation, superior to that of many other ML transition metal dichalcogenide (TMDC) detectors. More interestingly, ML WS2 devices with microtips can effectively solve the contradictory problem between large photoresponsivity and rapid switching speed. The excellent photoresponse performances of ML WS2 with microtips should be attributed to their high carrier mobility, sharp emission edge, ultrahigh quantum yield, and unique planar FE device structure. Ourresearch may shed new light on exploring the fabrication technology and photosensitive mechanism of two dimensional (2D) material-based planar FE photodetectors.

Arrays of nano and micro inverted silicon structures via copper catalyzed chemical etching for effective light trapping

Nano/micro structuring of silicon (Si) via chemical approaches have currently acquired a lot of research interests owing to their excellent light trapping abilities in broad spectral range. Here, a comprehensive study on the fabrication of nano/micro-inverted structures via one-step copper (Cu) catalyzed chemical etching (CuCCE) of solar grade n-Si wafers employing the aqueous solution of Cu(NO3)2/HF/H2O2 in various compositions and their light trapping ability are reported. Influence of etch parameters, namely, Cu2+ ions concentration, HF/H2O2 compositions and surface properties of the wafers are systematically investigated on the evolution of different inverted nano- and micro-structured Si surfaces. Arrays of micron-sized inverted pyramids (μ-IP) and nano-micro-hybrid inverted pyramids (n-μ-HIP) have been fabricated on partial polished and as-cut solar grade Si wafers respectively in an optimized compositions of the solution (Cu(NO3)2, HF and H2O2 at 5 mM, 4.6 M and 0.55 M respectively) at 50 °C after 15 min. The surfaces exhibit solar weighted reflection as low as <7% and <5% respectively for a broad spectral range (400–1000 nm; AM1.5G). The n-μ-HIP-Si arrays also exhibited ∼8 fold enhanced Raman signal. Isotropic thinning of Si wafers, nano-porous, and craters like Si structures could also be obtained under appropriate etch conditions. Mechanism of the formation of such inverted structures under different etch conditions have been explained based on the Cu catalyzed, self-controlled electrochemical redox reactions and balancing act of anisotropic-isotropic etching of Si in the CuCCE etch bath. The excellent light trapping properties of the nano/micro structures is also explained. Moreover, the ‘proof of concept’ of application of the inverted nano/micro light trapping structures in the PEDOT:PSS/n-Si hybrid heterojunction solar cells with enhanced performance has also been shown. The Si surfaces via simple yet effective CuCCE process may find applications in other photosensitive devices as well as surface enhanced Raman spectroscopy.

Centimeter-Transferable III-Nitride Membrane Enabled by Interfacial Adhesion Control for a Flexible Photosensitive Device.

Flexible III-nitride-based optoelectronic devices are crucial for the next-generation foldable/wearable lighting sterilization and sensor working in the ultraviolet (UV) region. However, the strong bonding effect at the epitaxial interface of III-nitride and bare sapphire substrate makes it difficult for epilayer separation and flexible applications. Although the emerging van der Waals epitaxy (vdWE) with graphene insertion layer offers a feasible route for weakening the interfacial adhesion, the intact centimeter-transferable III-nitride membrane still remains challenging. The spontaneous delamination occurs due to the too weak interfacial adhesion of pure vdW force, and on the contrary, the structural damage of graphene by high-temperature hydrogen etching during the III-nitride growth might also cause separation failure. Up to now, the efficient control of vdWE interfacial adhesion is still an on-going research hotspot. Herein, we demonstrate the interfacial adhesion control of III-nitride vdWE by utilizing graded high-temperature nitridation treatment of the graphene insertion layer, which generates defects and N doping in different levels. The corresponding epitaxial modes of pure-vdWE, quasi-vdWE, and mixed epitaxy are achieved according to the interfacial adhesion difference. It reveals that the quasi-vdWE enabled by small graphene defects and proper N doping triggers the low formation energy for AlN nucleation; meanwhile, the proper interfacial adhesion ensures the growth integrality and intact separation of III-nitride membrane in the centimeter scale. The UV resin-assisted bonding technique is proposed for the successful transfer of III-nitride onto a flexible substrate. The flexible photodetector is fabricated by using a graphene monolayer as the photocarrier transport channel, and it achieves a high device yield of 90%, retaining ∼60% of its initial performance after 250 bending cycles. This work offers the promising strategy for controlling vdWE interfacial adhesion, and the separable and transferable III-nitride membrane lays the foundation for advances of future UV foldable and wearable devices.

Fabrication of Schottky Barrier Diodes Utilizing Schiff Base Compounds and Metal Complexes with Schiff Base Ligands

AbstractFabrications of different kinds of diodes with various types of materials are the trends of modern research. In recent times organic materials and metal complexes containing organic ligands are chosen preferably for the fabrication of Schottky barrier diodes. Utilizations of Schiff‐base compounds and Schiff base containing metal complexes in the making of Schottky barrier diodes are immensely appreciated because the syntheses of Schiff‐base compounds are quite straightforward, less expensive and require less time. Large scale production of Schiff base materials is comparatively easier because their syntheses involve facile condensation reaction and their optical properties can be easily tuned by introducing simple substituent groups. Designing appropriate molecular structure plays pivotal role in the conducting properties of the materials. The molecular systems with exiting conducting properties can be utilized for the fabrication of such active electronic device. Sometimes, the specific structural arrangements enhance the charge flow upon illumination of light. These materials can be used in making photosensitive diode devices. In this context, this review, comprising of a collection of research articles regarding Schottky diode device based on Schiff bases and metal complexes with Schiff base ligands, may be helpful for the researchers of the relevant field.

47‐2: Photosensitive characteristics and application of photosensitive device based on TFT process

A glass‐based TFT (thin film transistor circuit) module with ambient light detection function was designed and manufactured on the display panel, and the photoelectric characteristics of TFT photosensitive devices were measured and obtained. After the data analysis and processing, the photoelectric characteristic curves with good linearity were obtained. After algorithmically optimizing the intrinsic data, the thin‐film transistor photosensitive element achieved the same photoelectric characteristic as the silicon‐based photosensitive element. Measurements of the photoelectric characteristics of the TFT photosensitive device showed that the photoelectric performance of the sensor is repeatable and relatively undetermined. The photoelectric characteristics demonstrate the corresponding relationship of multiple direction functions. Different products show different current values under the same illumination, but the overall photoelectric characteristics still maintain the trend of multiple direction functions. In the experiment, 200 TFT photosensitive device units were connected into a set of photosensitive elements array, and placed under the ambient illumination of 0~30000 LUX. The output current range of the photosensitive array after parallel connection is 0~200 mA. The results indicate that the photoelectric characteristic of TFT photosensitive device has linear relationship after effective data processing and algorithm computing. After testing with different products, the device characterizes the ambient light with less than 5% accuracy. Therefore, the glass‐based TFT module with ambient light detection function can accurately reflect the data of ambient light, realizing the practicability of the photosensitive device based on TFT technology.

Hydrophobic-Hydrophilic Block Copolymer Mediated Tuning of Halide Perovskite Photosensitive Device Stability and Efficiency.

The polymer additive strategy provides a facile and cost-effective way for passivating defects and trap sites at the grain boundaries and interfaces and acting as a barrier against the external degradation factors in perovskite-based devices. However, limited literature exists discussing the integration of hydrophobic and hydrophilic polymer additives in the form of a copolymer within the perovskite films. The inherent difference in the chemical structure of these polymers and their interaction with perovskite components and the environment leads to critical differences in the respective polymer-perovskite films. The current work utilizes both homopolymer and copolymer strategies to understand the effect of polystyrene (PS) and polyethylene glycol (PEG), two common commodity polymers, over the physicochemical and electro-optical properties of the as-fabricated devices and the distribution of polymer chains across the depth of perovskite films. The hydrophobic PS integrated perovskite devices PS-MAPbI3, 36 PS-b-1.4-PEG-MAPbI3, and 21.5 PS-b-20-PEG-MAPbI3 outperform hydrophilic PEG-MAPbI3 and pristine MAPbI3 devices and exhibit higher photocurrent, lower dark currents, and greater stability. A critical difference is also observed in the stability of devices, where rapid decay of performance is observed in the pristine MAPbI3 films. The deterioration in performance is highly limited for hydrophobic polymer-MAPbI3 films as they maintain 80% of their initial performance.

Advanced TPU/ZnS:Al Flexible Film with Thermo-Force-Optical Response for Smart Clothing

With the continuous development of science and technology, smart sensing wearables have gradually entered people’s lives. However, the prepared wearable material has poor air permeability, poor fit, and does not have multiple modal excitations. In addition, it is not waterproof or even wearable at low temperatures. In this work, a thermoplastic polyurethane (TPU) and ZnS:Al composite film with excellent air permeability has been developed. The TPU/ZnS:Al flexible film can be prepared on a large scale by solution blow spinning (SBS). This fiber membrane can realize the dual response of temperature and stress, and cooperate with the light sensor to realize the transmission of intelligent information. This nanofiber membrane doped with ZnS:Al exhibits a uniform distribution, maintains excellent tensile properties and flexibility, and can adapt to any perfect shape of the fitting surface. Even the average air permeability can be as high as 300 mm s−1, which is 600 times that of conventional spraying methods. The Al introduced in ZnS:Al can stimulate the composite film to emit light, and the luminescence effect can be maintained for about 1 min. These results provide new ideas for the large-scale fabrication of integrated stimulus-responsive photosensitive intelligent wearable devices for various applications.