Self-powered Ultraviolet Photodetector Research Articles

High-performance self-powered UV photodetectors using SnO2 thin film by reactive magnetron sputtering

Self-powered UV photodetector (UVPD) operates without the need for an external energy source and contributes to global energy conservation. With ongoing innovation, self-powered PDs are becoming increasingly appealing for industrial and innovation applications such as advanced environmental monitoring and communication devices. This study investigates the influence of varying working pressures (ranging from 3 to 15 mTorr) during reactive magnetron sputtering on the crystalline structure, surface morphology, and performance of SnO2 thin film photodetectors, aiming to fabricate self-powered UVPDs. The SnO2-based UVPD demonstrates exceptional self-powered UV photodetection capabilities, characterized by a sensitivity of 6.41×105%, responsivity of 0.09 mA/W, and detectivity of 2.99×1010 Jones. In addition, SnO2-based UVPD possesses a switching photo response and recovery time of 0.75 and 0.99 s. Henceforth, it was observed that 8 mTorr SnO2 thin film exhibits exceptional stability, superior photodetector performance, and remarkable repeatability, rendering them highly suitable for UVPD applications. Notably, these films demonstrate sustained functionality for approximately 100 days without necessitating encapsulation. These excellent results confirm that SnO2 thin films are suitable for fabricating future smart optoelectronics devices.

Fabrication of Al doped α-GaOOH nanorod arrays on FTO for self-powered photoelectrochemical solar-blind UV photodetectors

Abstract Al doped α-GaOOH nanorod arrays were grown on FTO via hydrothermal processes by using gallium nitrate and aluminium nitrate mixed aqueous solutions with fixed 1:1 mole ratio as precursors. With increasing the gallium nitrate precursor concentrations, the Ga/Al atom ratio in nanorod arrays increase from 0.36 to 2.08, and the length becomes much longer from 650 nm to 1.04 μm. According to the binding energy difference between Ga 2p3/2 core level and its background in XPS, the bandgap is estimated to be around 5.3±0.2 eV. Al doped α-GaOOH nanorod array/FTO photoelectrochemical (PEC) photodetectors shows enhanced self-powered solar-blind UV photodetection properties, with the decrease of Ga precursor concentrations. The maximum responsivity at 255 nm is 0.09 mA/W, and the fastest response time can reach 0.05s. The improved photoresponse speed is ascribed from much shorter transportation route, accelerated carrier recombination by recombination centers, and smaller charge transfer resistance at the α-GaOOH/electrolyte interface with decreasing the gallium nitrate precursor concentrations. The stability and responsivity should be further improved. Nevertheless, this work firstly demonstrates the realization of self-powered solar-blind UV photodetection for α-GaOOH nanorod arrays on FTO via Al doping.

Photoelectrochemical properties of self-powered corundum-structured Ga2O3nanorod array/fluorine-doped SnO2photodetectors modulated by precursor concentrations.

Herein, corundum-structured Ga2O3(α-Ga2O3) nanorod array/fluorine-doped SnO2(FTO) structures have been fabricated by hydrothermal and thermal annealing processes with different precursor concentrations from 0.01 M to 0.06 M. The diameter and length of the nanorod arrays are much larger with increasing precursor concentrations due to more nucleation sites and precursor ions participating in the reaction procedures. The optical bandgap decreases from 4.75 eV to 4.47 eV because of the tensile stress relieving with increasing the precursor concentrations. Based on self-powered photoelectrochemical (PEC) photodetectors, the peak responsivity is improved from ~0.33 mA/W for 0.06 M to ~1.51 mA/W for 0.02 M. Schottky junctions can be formed in PEC cells. More photogenerated carriers can be produced in wider depletion region. From Mott-Schottky plots, the depletion regions become much wider with decreasing the precursor concentrations. Therefore, the enhance responsivity is owing to the wider depletion regions. Due to the reduced possibility of photogenerated holes captured by traps ascribed from fewer green and yellow luminescence defects, smaller charge transfer resistance, and shorter transportation route, the decay time becomes much faster through decreasing the precursor concentrations. Compared with the other self-powered α-Ga2O3-nanorod-array-based PEC photodetectors, it shows the fastest response time (decay time of 0.005 s/0.026 s) simply modulated by precursor concentrations for the first time without employing complex precursors, seed layers or special device designs. Compared with other high-responsivity monoclinic Ga2O3(α-Ga2O3) self-powered photodetectors, our devices also show comparable response speed with simple control and design. This work provides the realization of fast-speed self-powered Ga2O3based solar-blind ultraviolet photodetectors by simple modulation processes and design, which is a significant guidance for their applications in warnings, imaging, computing, communication and logic circuit, in the future.

Highly Wavelength-Selective Self-Powered Solar-Blind Ultraviolet Photodetector Based on Colloidal Aluminum Nitride Quantum Dots.

Colloidal quantum dots are semiconductor nanocrystals endowed with unique optoelectronic properties. A major challenge to the field is the lack of methods for synthesizing quantum dots exhibit strong photo-response in the deep-ultraviolet (DUV) band. Here, a facile solution-processed method is presented for synthesizing ultrawide bandgap aluminium nitride quantum dots (AlN QDs) showing distinguished UV-B photoluminescence. Combined with the strong optical response in solar blind band, a solution-processed, self-powered AlN-QDs/β-Ga2O3 solar-blind photodetector is demonstrated. The photodetector is characterized with a high responsivity of 1.6mAW-1 under 0V bias and specific detectivity 7.60 × 10-11 Jones under 5V bias voltage with good solar blind selectivity. Given the solution-processed capability of the devices and extraordinary properties of AlN QDs, this study anticipates the utilization of AlN QDs will open up unique opportunities for cost-effective industrial production of high-performance DUV optoelectronics for large-scale applications.

Self-Powered UV Photodetector Construction of the P(EDOS-TTh) Copolymer-Modified ZnO Nanoarray.

To solve the problem that zinc oxide nanorods (ZnO NRs)-based self-powered ultraviolet (UV) photodetectors cannot obtain both higher responsiveness and shorter response time, P(EDOS-TTh) was prepared using 3,4-ethylenedioxyselenphene (EDOS) and terthiophene (TTh) as copolymers, which modify the ZnO NRs surface, and the ZnO/P(EDOS-TTh) P-N junction self-powered UV device is assembled. The effect of the number of electrochemical polymerization cycles on the UV photodetection performance of ZnO/P(EDOS-TTh) P-N heterojunction was studied by adjusting the number of electrochemical polymerization cycles at the monomer molar ratio of 1:1. Benefiting from the enhanced built-in electric field of the ZnO/P(EDOS-TTh) interface, balancing photogenerated carriers, and charge separation and transport. The results show that the contact between N-type ZnO NRs and P-type P(EDOS-TTh) is best when the number of polymerization cycles is 3, due to the fact that EDOS-TTh and ZnO NRs form excellent P-N heterojunctions with strong internal electric fields, and the devices show good pyroelectric effect and UV photodetection performance. Under 0 V bias and 0.32 mW/cm2 UV irradiation, the responsivity (R) of ZnO/P(EDOS-TTh) reaches 3.31 mA/W, the detectivity (D*) is 7.25 × 1010 Jones, and the response time is significantly shortened. The rise time is 0.086 s, which exhibited excellent photoelectric properties and stability. UV photodetection performance with high sensitivity and fast response time is achieved.

A self-powered and flexible deep ultraviolet photodetector based on NiO/Ga2O3 heterojunction and employing stable MXene electrodes

Wearable photodetectors (PDs) have gained significant attention for their importance in smart monitoring applications. The future of wearable electronics emphasizes the development of self-powered devices, necessitating precise material selection and fabrication techniques to achieve optimal electrical and mechanical performance. Traditionally, p-n photodetector junctions have been fabricated using non-oxide materials such as GaN and SiC, but these materials are prone to conductivity degradation due to oxidation of the p-type component. In this investigation, we have successfully engineered a NiO/Ga2O3 heterojunction deep ultraviolet photodetector on both rigid and flexible substrates. The flexible version incorporates Ti3C2TX MXene electrodes, which offer exceptional mechanical stability even in harsh mechanical circumstances. Our photodetector showcases a responsivity of 47 μA/W, a photoresponse time of 0.24 s, a specific detectivity (D*) of 3.84 ×109 jones, and an Ilight/Idark ratio of 121. It also demonstrates excellent repeatability under 254 nm light exposure. The NiO/Ga2O3 heterojunction photodetector exhibits outstanding optoelectronic performance even under harsh mechanical conditions, specifically withstanding 40% stretchability and various bending angles while maintaining self-powered capabilities. This makes it ideal for wearable devices, meeting requirements for both durability and functionality.

Temperature-Dependent Structure–Property Relationship of Mn-Doped Cs2AgInCl6 Thin Films Impacts Its Application as a Self-Powered UV Photodetector

Temperature-Dependent Structure–Property Relationship of Mn-Doped Cs₂AgInCl₆ Thin Films Impacts Its Application as a Self-Powered UV Photodetector

High-Performance Self-Powered Photoelectrochemical Ultraviolet Photodetectors Based on an In2O3 Nanocube Film.

Ultraviolet photodetectors (UV PDs) have attracted significant attention due to their wide range of applications, such as underwater communication, biological analysis, and early fire warning systems. Indium oxide (In2O3) is a candidate for developing high-performance photoelectrochemical (PEC)-type UV PDs owing to its high UV absorption and good stability. However, the self-powered photoresponse of the previously reported In2O3-based PEC UV PDs is unsatisfactory. In this work, high-performance self-powered PEC UV PDs were constructed by using an In2O3 nanocube film (NCF) as a photoanode. In2O3 NCF photoanodes were synthesized on FTO by using hydrothermal methods with a calcining process. The influence of the electrolyte concentration, bias potential, and irradiation light on the photoresponse properties was systematically studied. In2O3 NCF PEC UV PDs exhibit outstanding self-powered photoresponses to 365 nm UV light with a high responsivity of 44.43 mA/W and fast response speed (20/30 ms) under zero bias potential, these results are superior to those of previously reported In2O3-based PEC UV PDs. The improved self-powered photoresponse is attributed to the higher photogenerated carrier separation efficiency and faster charge transport of the in-situ grown In2O3 NCF. In addition, these PDs exhibit excellent multicycle stability, maintaining the photocurrent at 98.69% of the initial value after 700 optical switching cycles. Therefore, our results prove the great promise of In2O3 in self-powered PEC UV PDs.

Multi-effect coupling enhanced self-powered heterojunction ultraviolet photodetector with ultra-low detection limit

Convenient, small-sized, and self-powered sensor units are easier to integrate, making them the future development direction of photodetectors. GaN materials with wide band gap are powerful candidates for UV detection, but most GaN based self-powered UV photodetectors have poor detection ability for the weak UV light, which limits their applications. This study reports a self-powered UV photodetector based on BaTiO3/GaN heterojunction, which can detect ultra-weak UV light at a minimum of 0.68 nW/cm2 by coupling the ferroelectric polarization, anti-reflection effect, and pyro-phototronic effect. The polarized BaTiO3 thin film on the surface of GaN has an enhanced residual polarization field and generated anti-reflection effect, which can regulate the heterojunction band structure, suppress the dark current and minimize surface reflection of GaN. Simultaneously enhanced pyro-phototronic effect can significantly improve the response speed and responsivity of the device. The response time and recovery time of the device are as low as 8.794 ms and 5.018 ms. The maximum responsivity and detectivity are 88.206 mA/W and 7.392 × 1013 Jones, respectively, increased by 359% and 6065% compared to the device before polarization. Thanks to excellent material stability, the device has a sensitive and uniform response to continuously incident UV light. In addition, by simulating flame generation, it has been proven that the device has brilliant performance in flame detection and can achieve remote monitoring and fire warning functions. These results can promote the potential application of self-powered UV photodetectors based on BaTiO3/GaN heterojunction in environmental monitoring and space communication fields.

Piezoelectricity Enhanced Self-Powered Solar-Blind Ultraviolet Photodetectors Based on Ga2O3/ZnO Heterojunction

Piezoelectricity Enhanced Self-Powered Solar-Blind Ultraviolet Photodetectors Based on Ga₂O₃/ZnO Heterojunction

Performance-Boosted AgNWs@ZnO:Sb Microwire/n-Si Heterojunction Self-Powered Ultraviolet Photodetector by Coupling Pyro-Phototronic and Plasmonic Effects

Performance-Boosted AgNWs@ZnO:Sb Microwire/n-Si Heterojunction Self-Powered Ultraviolet Photodetector by Coupling Pyro-Phototronic and Plasmonic Effects

MXene/AlGaN van der Waals heterojunction self-powered photodetectors for deep ultraviolet communication

Self-powered deep ultraviolet (DUV) photodetectors (PDs) have attracted considerable attention in environmental, industrial, and military fields because of their power-independent and environmentally sensitive photodetection. However, DUV PDs based on traditional thin film structures are limited by the low intrinsic mobility of aluminum-gallium nitride (AlGaN) and the large barrier width of the heterogeneous structure, which makes it difficult to achieve efficient spontaneous separation, resulting in lower responsiveness and a slow response speed. Herein, a 2D/3D DUV PD based on the MXene, niobium carbide (Nb2CTx)/AlGaN van der Waals heterojunctions (vdWHs) has been proposed. The as-prepared DUV PDs revealed self-powered properties with a high responsivity of 101.85 mA W−1, as well as a fast response (rise/decay time of 21/22 ms) under 254 nm DUV illumination, thanks to the excellent electrical conductivity and tunable work function of the MXene. It also showed a large linear dynamic range of 70 dB under −2 V bias because of the strong DUV absorption of MXene/AlGaN vdWH, and the enhanced carrier mobility under high illumination density. This study presents an easy processing route to fabricate high-performance self-powered DUV PDs based on MXene/AlGaN vdWHs for DUV communication.

Improved photodetection performance of self-powered UV photodetector based on PZT/CuSCN heterojunction

Ferroelectric materials have garnered substantial research interest in the development of novel self-powered ultraviolet (UV) photodetectors due to their polarization-induced photovoltaic (PV) effect. However, ferroelectric-based self-powered UV detectors reported so far exhibit low photocurrent, responsivity, and detectivity that hindered their integration with existing platforms. Herein, we fabricate PbZr0·52Ti0·48O3 (PZT)/CuSCN heterojunction to realize a self-powered UV detector, exhibiting enhanced photodetection owing to the constructive coupling of the robust depolarization field of PZT ferroelctric, and built-in electric field at PZT/CuSCN interface. The device displays remarkable reproducibility and a substantial light/dark current ratio of ∼24 under illumination of 320 nm light. Moreover, the responsivity and detectivity of the device are as high as 0.125 ± 0.011 W/A and 6.931 ± 0.009 × 1010 Jones under light density of 8.11 W/cm2, respectively. This study presents a viable and effective approach for enhancing the photodetection performance of ferroelectric-based self-powered UV detectors.

Electrospun vanadium oxide hollow nanofibers based supercapacitor inspired triboelectric nanogenerator as self-powered visible-blind ultraviolet photodetector

Self-powered visible-blind ultraviolet (UV) photodetectors have emerged as sustainable alternatives in various sectors, including security, surveillance, and environmental monitoring. So, we report a vanadium oxide (V2O5) hollow nanofibers-based supercapacitor-inspired triboelectric nanogenerator (STENG) as a self-powered visible-blind UV photodetector. A novel designed STENG is fabricated using electrospun V2O5 hollow nanofibers-based coated on indium tin oxide coated polyethylene terephthalate sheet (ITO/PET) on top side and a layer of polyvinyl alcohol (PVA) & sulphuric acid over multi-walled carbon nanotubes (MWCNT) coated graphite sheet on bottom side. The optimized STENG demonstrates 34 V peak-to-peak open circuit voltage (Voc) and 2 μA of peak-to-peak short circuit current (Isc) by applying force via finger tapping. However, STENG's performance improves significantly to deliver 280 V Voc (peak-to-peak), and 6 μA Isc (peak-to-peak) with 0.49 W/m2 power density at 100 MΩ load resistance due to electrochemical charging. The output voltage of the STENG increases by 400 % under UV light, which refers to the excellent performance of STENG as a self-powered visible-blind UV photodetector with 266 V/W responsivity at 2.5 mW/cm2 intensity. Hence, the as-fabricated V2O5 hollow nanofibers-based STENG not only paves the way to fabricate a high-performance energy harvester, but can also be used as a self-powered UV-photodetector.

Self-powered deep ultraviolet photodetector based on p-CuI/n-ZnGa2O4 heterojunction with high sensitivity and fast speed.

Self-powered deep ultraviolet photodetectors (DUV PDs) are essential in environmental monitoring, flame detection, missile guidance, aerospace, and other fields. A heterojunction photodetector based on p-CuI/n-ZnGa2O4 has been fabricated by pulsed laser deposition combined with vacuum thermal evaporation. Under 260 nm DUV light irradiation, the photodetector exhibits apparent self-powered performance with a maximum responsivity and specific detectivity of 2.75 mA/W and 1.10 × 1011 Jones at 0 V. The photodetector exhibits high repeatability and stability under 260 nm periodic illumination. The response and recovery time are 205 ms and 133 ms, respectively. This work provides an effective strategy for fabricating high-performance self-powered DUV photodetectors.

Highly sensitive self-powered solar-blind ultraviolet photodetectors based on n-Zn1-xFexO/p-Si heterojunctions

The pristine and iron-doped ZnO thin films were fabricated on p-type silicon and glass substrates using the radio-frequency magnetron sputter deposition technique. The structural, morphological, and electrical properties of the deposited thin films were analyzed using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), and I-V characteristics. XRD analysis revealed the preferential growth of ZnO along the c-axis, with lattice parameter (c) values of 5.216, 5.234, and 5.241 Å for the pristine ZnO, Zn0.97Fe0.03O, and Zn0.95Fe0.05O thin films, respectively. The crystallite sizes were measured to be 13.2 nm, 16.2 nm, and 18.3 nm for the respective films. The elemental analysis of the deposited films was done under X-ray photoelectron spectroscopy (XPS), which revealed the concentrations of iron Zn0.97Fe0.03O, and Zn0.95Fe0.05O thin films were 2.93 at% and 5.14 at%, respectively. Raman spectroscopy confirmed the presence of the hexagonal wurtzite structural form in the deposited films. The I-V characteristics of the deposited films confirmed the formation of a heterojunction between the film and the silicon substrate. Furthermore, the constructed heterojunction devices were evaluated for their ability to detect ultraviolet (UV) radiations of wavelengths 365 nm and 254 nm. The devices exhibited response and recovery times of less than 1 s. The detectivity values were found to be 0.321 ×1011, 1.051 ×1011, and 2.992 ×1011 Jones for the ZnO/p-Si, Zn0.97Fe0.03O/p-Si, and Zn0.95Fe0.05O/p-Si devices, respectively, under a fixed illumination intensity of 0.812 mW/cm2 for a UVA source with a wavelength of 365 nm. These results confirm the excellent photodetection ability of the constructed devices. The mechanism of UV radiation detection by the devices has also been extensively discussed.

High-performance photoelectrochemical (PEC) type self-powered ultraviolet photodetectors (PDs) based on three-dimensional ZnO film/carbon fiber paper

Novel photoelectrochemical ultraviolet detection technologies based on semiconductor/electrolyte heterojunctions have attracted significant attention due to their cost-effective fabrication and self-powered characteristic. In this study, ZnO films were deposited on three-dimensional carbon fiber paper (3D CFP) using a one-step sputtering method, resulting in the preparation of 3D ZnO/CFP composites as photoanodes for photoelectrochemical (PEC) type photodetectors (PDs). The fabricated device demonstrates outstanding photoelectrochemical performance, showcasing a remarkable responsivity of approximately 31.76 mA/W, a detectivity of 3.06 × 1012 jones, and a rapid photoresponse time of 76.51/48.51 ms. Furthermore, the device exhibits exceptional photoresponse stability during cycling tests. The unique structure of 3D CFP, composed of intertwined carbon fiber in three dimensions, offers an enlarged specific surface area and efficient carrier transport pathways for the photoanode in self-powered PEC-PDs. This characteristic facilitates effective electrolyte diffusion throughout the entire film, as well as efficient transport of photo-generated charge carriers, thereby significantly enhancing the overall performance of the PEC-PDs. This study affirms the effectiveness of the synergistic interaction between 3D CFP and ZnO film for advanced UV photodetectors, demonstrating both mass production viability and promise for the future of photoelectrochemical detection technology.

Regulating The Electronic Configuration of Low-Dimensional Hybrid Perovskites via Organic Cations for Self-Powered Ultraviolet Photodetectors.

Ultraviolet photodetectors (UPDs) based on low-dimensional halide perovskites have undergone rapid development. Here, regulation ofthe electronic configuration of low-dimensional hybrid perovskites are reported via organic cations for self-powered UPDs. For the first time, it is determine that the rational design of organic cation phenyl alkylammonium can effectively prevent phonon scattering thus increasing charge carrier extraction in low dimensional lead chlorine perovskite thin-films. As a result, the exciton-binding energy can be reduced to 62.91meV in (PMA)2 PbCl4 perovskite films with a charge-carrier mobility of 0.335cm2 V-1 s-1 . The fabricated (PMA)2 PbCl4 -based self-powered UPDs has achieved a high detectivity of 6.32 × 1013 jones with a low noise current of 0.35pAHz-1/2 under zero bias. A further demonstration of images with high UV to visible light rejection ratio under weak-light illumination of 70nWcm-2 highlights the feasible potential application of low-dimensional perovskite.

Integrating interface engineering and plasmonic effect to boost photoresponse performance of ZnO:Ga/GaN heterojunction self-powered UV photodetectors

The ability to function without an external power supply makes photodetectors highly promising for use in a new generation of wirelessly and independently operated ultraviolet (UV) photodetection and imaging systems. However, self-powered photodetectors' high dark current, inadequate light harvesting, and poor carrier separation prevent them from attaining high-efficiency UV photodetection and imaging. Herein, a high-performance heterojunction UV photodetector consisting of a single Ga-doped ZnO microwire enshrouded by Ag nanowires (AgNWs@ZnO:Ga MW), a MgO electron blocking layer, and a p-type GaN wafer was proposed. Taking full advantage of the interface engineering and plasmonic effects, the AgNWs@ZnO:Ga MW/MgO/GaN photodetector achieves high photodetection performance with an excellent responsivity of 262 mA/W, a remarkable external quantum efficiency of 92.37%, and a high detectivity of 1.966 × 1012 Jones under 370 nm illumination with power density of 0.22 mW/cm2. Furthermore, it also demonstrates ultrafast pulsed photoresponse speed with a rise/fall time of 3.64 μs/252 μs. An UV imaging system is designed based on the AgNWs@ZnO:Ga MW/MgO/GaN self-powered photodetector, allowing for high-quality, accurate, and distinct object imaging. This work combines interface engineering and plasmonic effects for achieving high-performance UV photodetection, which provides a strategic approach to the development of highly efficient optoelectronic devices.

Self-powered solar blind ultraviolet photodetector based on amorphous (In0.23Ga0.77)2O3/bixbyite (In0.67Ga0.33)2O3 heterojunction

Self-powered solar-blind ultraviolet photodetectors are considered for potential applications in secure communication and space detection. However, high-quality p-type wide bandgap semiconductors are nonexistent due to the self-compensation effect, which makes the design of p-n homojunction photodetectors a challenging proposition to date. In this work, a self-powered solar-blind ultraviolet photodetector is fabricated and discussed, based on a novel heterojunction of (InxGa1−x)2O3 ternary alloy films with two different compositions, which has a flexible design and can be easily fabricated for different applications. The heterojunction consists of an amorphous (In0.23Ga0.77)2O3 on the top of a bixbyite (In0.67Ga0.33)2O3 film prepared by radio frequency magnetron sputtering. The amorphous (In0.23Ga0.77)2O3/bixbyite (In0.67Ga0.33)2O3 heterojunction photodetector exhibits a responsivity of 5.78 mA/W, a detectivity of 1.69 × 1011 cm Hz1/2 W−1, and a high solar-blind UV (248 nm)/visible light (450 nm) rejection ratio of 1.39 × 103 at zero bias, suggesting decent spectral selectivity and high performance. The responsivity and peak wavelength of this photodetector can be tuned by the film thickness of the amorphous (In0.23Ga0.77)2O3. This work provides a new design for self-powered solar-blind UV detectors based on ternary alloy heterojunctions.