Self-powered UV Research Articles

Self-Powered Ga₂O₃ MSM Solar-Blind UV PDs With Asymmetric Electrodes for Optical Communications

Self-Powered Ga₂O₃ MSM Solar-Blind UV PDs With Asymmetric Electrodes for Optical Communications

Spraying-Deposited Transparent p-Type Sn-Doped CuI Film and Its Ultrahigh-Speed Self-Powered Photodetector.

The exploitation of simply processed p-type semiconductors and photodetectors with promising optoelectrical properties remains challenging yet essential for current and future advanced optoelectronic applications. Transparent p-type CuI and Sn-doped CuI (Cu-Sn-I) films and their self-powered photodetectors have been successfully fabricated by the spraying method. It is found that the incorporation of Sn dopants enhances the optical, electrical, and photoelectric properties of CuI thin films as well as their corresponding self-powered heterojunction photodetectors. This improvement of the optoelectrical properties of the Cu-Sn-I film and its photodetector can be attributed to the adjustment of the acceptor defect level and increased hole concentration resulting from Sn doping. The Cu-Sn-I/n-Si photodetector exhibits a responsivity of 10.7 mA/W, a detectivity of 6.79 × 1011 Jones, and a response time of 77 μs/30 μs (0 V bias). The response time exhibits the fastest rise and decay times compared with the other CuI-based self-powered UV photodetectors in recent years, showcasing promising applications in the realm of transparent electronics moving forward. This study also presents an effective strategy for enhancing the electrical properties of p-type semiconductors and devices through effective doping.

Self-Powered UV Photodetectors Based on Hydrothermal Barium Titanate Film Modified With Reduced Graphene Oxide Nanolayer

Self-Powered UV Photodetectors Based on Hydrothermal Barium Titanate Film Modified With Reduced Graphene Oxide Nanolayer

ZnO@NiO core-shell heterojunction photoanode modified with NiOOH co-catalyst for high-performance self-powered photoelectrochemical-type UV photodetector

ZnO, a promising photoanode material, faces significant challenges in achieving high-efficient photoelectrochemical (PEC) type UV photodetectors due to inadequate charge separation and sluggish surface reaction kinetics. Constructing heterojunction nanostructures by coupling of p-NiO to n-ZnO nanowire arrays with well-aligned energy band positions presents a feasible strategy for enhancing PEC-type photodetector performance. Herein, we demonstrate that the designed ZnO@NiO core–shell nanowire arrays form a spatial charge transfer channel, facilitating efficient generation and extraction of charge carriers. The exceptional catalytic properties of NiOOH, derived from the transformation of NiO in an aqueous alkaline environment, serve as a potent co-catalyst, effectively accelerating the kinetics of the surface oxygen evolution reaction. Benefiting from the synergistic effect of the heterojunction and cocatalyst, the optimized photoanode achieves a high responsivity of 438.36 mA/W, a large detectivity of 4.85 × 1012 Jones, and rapid response time of 150.05/150.26 ms, while simultaneously exhibiting long-time PEC stability. This work highlights the critical role of nanostructure design in developing high-performance self-powered UV photodetectors.

Ferro-Pyro-Phototronic Effect Enhanced Self-Powered UV Photodetectors Based on BaTiO3@MXene/4H-SiC Heterojunction

Ferro-Pyro-Phototronic Effect Enhanced Self-Powered UV Photodetectors Based on BaTiO₃@MXene/4H-SiC Heterojunction

Self-Powered Flexible Edible UV Sensors Based on Sustainable Materials Applicable for Food Packaging

Self-Powered Flexible Edible UV Sensors Based on Sustainable Materials Applicable for Food Packaging

Self-powered high performance UV photodetectors based on spin coated n-ZnO/p-Si heterostructure

Self-powered photodetectors with high responsivity and external quantum efficiency (EQE) are in great demand for various practical applications. This paper reports the fabrication and evaluation of self-powered, high-performing ultraviolet photodetectors with fast switching action. A p-n junction was formed by spin coating n-type ZnO on p-silicon substrates. The photodetector showed a responsivity of 0.15 A/W and an EQE of 52 %. The switching speed of devices was as low as 250 ms, even under zero bias. XRD analysis revealed the hexagonal wurtzite structure and AFM images confirmed the good quality of the films with roughness values as low as 2 nm. Defect analysis was done by photoluminescence studies. The molarity of the precursor solution and the annealing temperature were varied to optimize the performance. Sample with molarity 0.5 M annealed at 500 °C showed the best results.

Highly stable and self-powered ultraviolet photodetector based on Dion-Jacobson phase lead-free double perovskite

Metal halide perovskite materials present a wide array of opportunities for the development of high-performance optoelectronic devices, owing to their outstanding photoelectric properties. Compared with the lead-containing perovskites, stable and non-toxic organic-inorganic hybrid perovskites exhibit enhanced potential for future commercial applications. In this work, we developed a self-powered UV photodetector based on 2D Dion−Jacobson (DJ) phase lead-free double perovskite HAAg0.5Bi0.5Br4 (HA2+ = histammonium) perovskite with an on-off ratio up to 2.66 × 106, excellent specific detectivity of 6 × 1012 Jones, and response speed of 1.32 ms/118.4 μs. The light intensity related pyro-phototronic effect on 2D perovskite is thoroughly investigated. Temperature and light detection are realized through multi-energy coupling, which greatly improves the detection performance. Coupled pyro-phototronic current is calculated nearly 75 folds higher than that from the photoelectronic merely. As-prepared photodetector film shows excellent stability in normal environment, maintaining a value of 90 % to the initial performance after 500 cycles and 90 days. This work provides a new self-powered, stable and non-toxic candidate for the future UV photodetectors.

Boosting deep-ultraviolet photodetector performance via ferroelectric effect based on HfAlOx@PEI composite

In this study, hafnium-aluminum oxide (HfAlOx) was used as an effective active layer in a self-powered deep-ultraviolet (UV) photodetector. For the first time, we exploited the ferroelectric properties of crystalline HfAlOx to enhance device performance. The HfAlOx powder obtained at an annealing temperature of 850 °C exhibited the highest-intensity peak for the orthorhombic phase (o-phase), representing the ferroelectric property of the material. The HfAlOx particles were reduced to a small size using mechanical treatment to facilitate the preparation of a composite thin film with a polyethyleneimine (PEI) polymer matrix. First, the HfAlOx@PEI composite film-based photodetector demonstrated a remarkable on/off ratio of more than 103 and a rapid response (trise/tfall of 0.127/2.7 s) at zero bias under 254-nm UV illumination. Second, the photocurrent of the device was dramatically boosted under an external bias owing to the injection of carriers, supported by the ferroelectric effect of the o-phase HfAlOx. As a result, the external quantum efficiency and responsivity approached 2628 % and 5.37 A/W at −1 V bias, respectively. Furthermore, the device exhibited excellent photostability, demonstrating almost no change in the photocurrent after 1000 s of UVC irradiation. Our findings provide guidance for the preparation of optoelectronic devices, particularly self-powered high-performance UV photodetectors.

Enhancing Photoelectric Response of Self-powered UV and Visible Detectors Using CuO/ZnO NRs Heterojunctions.

Understanding the development and performance of UV photodetectors is crucial, given their extensive applications in both military and civilian sectors. The evolution of self-powered photodetectors, especially those based on heterojunction nanostructures, has demonstrated significant potential for enhancing both device efficiency and functionality. By exploring the effects of material composition and structural design, can optimize these devices for improved photoelectric response and energy efficiency. In this study, we prepared the CuO/ZnO NRs heterojunction photodetector on an ITO substrate to enhance photoelectric response of UV detectors. The fabrication process utilized the hydrothermal method and the spin coating technique. The effect of CuO concentration on the optical response of the photodetector under UV radiation at wavelengths of 405nm and 385nm was investigated. The samples were characterized using FESSEM, XRD, EDX, and UV-Vis spectra. The device is further distinguished by its standard I-V curves and photocurrent-time curves, which demonstrate the device's behavior under various light conditions. The prepared thin films are polycrystalline, with CuO layers displaying monoclinic phases and ZnO layers exhibiting a hexagonal wurtzite phase. All samples have the potential to exhibit photovoltaic properties and self-powered capabilities. Furthermore, the I-V curve confirms that the photocurrent mechanism of these junctions adheres to the recombination standard, in addition to demonstrating correction behavior. A sample with a CuO concentration of 0.1M shows the highest photosensitivity, reaching 340,700%, and a photocurrent gain (Iph/Idark) of 3,408 when exposed to light irradiation at 405nm. Additionally, it exhibits a rapid response time of 0.8s.

Precisely Tailoring Ferroelectric Photocurrent via Magnetic Spin Chain toward Efficient Self-Powered UV Photodetectors

Precisely Tailoring Ferroelectric Photocurrent via Magnetic Spin Chain toward Efficient Self-Powered UV Photodetectors

Flexo-Phototronic Boosted Self-Powered Ultraviolet Detection in ZnAl:Layered Double Hydroxide Nanosheets/NiO Heterostructure.

Developing self-powered and flexible optoelectronic sensors with high responsivity and speed is crucial for modern applications, motivating continuous efforts to enhance their performance. Flexo-phototronics is a less-explored but promising technique to elevate the performance of optoelectronics. Therefore, this work addresses the potential of utilizing the flexo-phototronic effect to enhance the performance of a flexible and self-powered ultraviolet photodetector (UV PD) based on ZnAl:LDH (layered double hydroxides) nanosheets (Ns)/NiO heterostructure. The vertically oriented ZnAl:LDH Ns are synthesized via a simple method involving the immersion of a sputtered 10% Al-doped ZnO thin film in deionized water at room ambient conditions. The fabricated PD exhibits an impressive response to 365 nm UV light, with high sensitivity in the order of 103. The device's photocurrent and responsivity are significantly enhanced by the flexo-phototronic effect, attributed to the flexoelectric properties of ZnAl:LDH Ns. Specifically, applying an inhomogeneous tensile strain of 2% boosted the device responsivity by 57.1% and improved its operational speed. Furthermore, a working model revealing the altered energy-band structure is demonstrated to elucidate the flexo-phototronic-induced boost in the photoresponse. The PD also demonstrated a sustainable performance under severe bending cycles, underlining the good flexibility of the device. The results presented in this study demonstrate a self-powered and flexible UV PD and provide a viable approach to augment the performance of optoelectronics through the flexo-phototronic effect.

Ultrafast response self-powered UV photodetectors based on ZnO/SiO2/Si heterojunction diodes

This paper presents ultrafast response, self-powered UV photodetectors (PDs) based on ZnO/SiO2/Si heterojunction diodes, utilizing zinc oxide (ZnO) nanorods as the photosensitive layer. This configuration results in photodetectors exhibiting unprecedentedly rapid response times, with rise and decay times reduced to 440 ns and 320 ns, respectively. Our study, focusing on ZnO nanorod PDs, not only demonstrates ultrafast response times but also highlights the role of hydrothermal synthesis temperature in tuning the devices’ performance. These findings represent a significant leap forward in the development of high-performance, self-powered UV PDs. The effects of different hydrothermal temperature on the morphology, crystal structure, and optoelectrical properties were systematically investigated using various characterization techniques, including field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) analysis, photoluminescence analysis, and current-voltage (I-V) measurements.

Synthesis of InAl-alloyed Ga2O3 nanowires for self-powered ultraviolet detectors by a CVD method.

Ga2O3 is a kind of wide-band gap semiconductor, which has great potential in deep ultraviolet detection because of its high efficiency and fast response. Doping can improve the photoelectric properties of Ga2O3 materials. In this paper, In and Al elements alloyed Ga2O3 nanowires (InAl-Ga2O3 NWs) were successfully grown on p-GaN using a cost-effective chemical vapor deposition method and a vertical structure. The GaN/InAl-Ga2O3 NWs p-n self-powered wide-gap UV photodetector (PD) was constructed based on sputtered gold film as the bottom and top electrodes, and spin coated with polymethyl methacrylate as the insulating layer in the vertical direction. The GaN/InAl-Ga2O3 UV PD exhibits excellent performances, including an extremely low dark current of 0.015 nA, a maximum photocurrent of about 16 nA at zero-bias voltage under 265 nm illumination, and a light-to-dark current ratio greater than 103. The responsivity is 0.94 mA W-1, the specific detectivity is 9.63 × 109 jones, and the good fast response/attenuation time is 31.2/69.6 ms. The self-powered characteristics are derived from the internal electric field formed between p-type GaN and n-type InAl-Ga2O3 NWs, which is conducive to the rapid separation and transfer of photogenerated carriers. This work provides an innovative mechanism of high-performance metal oxide nanowires for the application of p-n junction photodetectors, which can operate without any external bias.

High performance self-powered UV–visible photodetectors based on ZnO@CdS/PEDOS heterojunctions

In this study, we report the design and development of a high-performance self-powered UV–visible photodetector (UV-Vis PD) based on ZnO@CdS /poly(3,4- ethylenedioxyselenophene) nanoarrays (ZnO@CdS/PEDOS), in which ZnO nanorods (NRs) were modified with CdS to address the limitations of ZnO NRs-based photodetectors in detecting both UV and visible light. The findings of this study demonstrated that the modification of ZnO NRs with CdS led to the formation of a type II heterojunction. This modification not only enhanced the detection capability of the photodetectors under UV (365 nm) light but also enabled efficient detection under visible light (450 nm). The R and D* of the ZnO@CdS/PEDOS device were 7.68× 10−3 A/W and 5.62×1011 Jones, respectively, with a τr of 0.19 s using 0 V and a UV light power (365 nm) of 0.32 mW/cm2. In addition, using a bias voltage of 0 V and a visible light (450 nm) at 0.32 mW/cm2, the R was 2.53×10−3 A/W and D* was 3.41×1010 Jones of the device were, the τr/τf were 0.23/0.29 s, respectively. An excellent performance self-powered PD in the dual-wavelength range was constructed.

Enhanced Performance of Self-Powered Solar-Blind Deep UV Photodetectors Based on ZnGa2O4/Ga2O3 Heterojunctions

Enhanced Performance of Self-Powered Solar-Blind Deep UV Photodetectors Based on ZnGa₂O₄/Ga₂O₃ Heterojunctions

Self-powered stable high-performance UV–Vis–NIR broadband photodetector based on PVP-Cobalt@Carbon nanofibers/n-GaAs heterojunction

The self-powered PVP-Co@C nanofibers/n-GaAs heterojunction photodetector (HJPD) was fabricated by electrospinning of the nanofibers onto GaAs. An excellent rectification ratio of 6.60 × 106 was obtained from I–V measurements of the device in the dark. The I–V measurements of the fabricated device under 365 nm, 395 nm and 850 nm lights, as well as I–V measurements in visible light depending on the light intensity, were performed. The HJPD demonstrated excellent photodetection performance in terms of a good responsivity of ∼225 mA W−1 (at −1.72 V) and at zero bias, an impressive detectivity of 6.28 × 1012 Jones, and a high on/off ratio of 8.38 × 105, all at 365 nm wavelength. In addition, the maximum external quantum efficiency and NPDR values were 3495% (V = −1.72 V) and 2.60 × 1010 W−1 (V = 0.0 V), respectively, while the minimum NEP value was ∼10−14 W.Hz−1/2 for 365 nm at V = 0.V volts. The HJPD also exhibited good long-term stability in air after 30 d without any encapsulation.

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

Al doped α-GaOOH nanorod arrays were grown on FTO via hydrothermal processes by using gallium nitrate and aluminum nitrate mixed aqueous solutions with fixed 1:1 mole ratio as precursors. With increasing the gallium nitrate precursor concentrations, the Ga/Al atom ratios 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 x-ray photoelectron spectroscopy, the bandgap is estimated to be around 5.3 ± 0.2 eV. Al doped α-GaOOH nanorod array/FTO photoelectrochemical photodetectors show 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−1, and the fastest response time can reach 0.05 s. 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.

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.

ZnAl-LDH film for self-powered ultraviolet photodetection

Self-powered photoelectrochemical-type (PEC) ultraviolet photodetectors (UV PDs) have been rapidly developed owing to their low-cost fabrication and good photodetection. However, achieving high-performance and self-powered PEC UV PDs based on an individual material is still challenging. Therefore, developing more wide bandgap semiconductors for high-performance PEC UV PDs is attractive. Here, we demonstrate that ZnAl-LDH is suitable for self-powered PEC UV PDs with high responsivity and excellent wavelength selectivity for the first time. The responsivity is 29.25 ​mA/W (254 ​nm irradiation) and the UV/visible rejection ratio is 1037, surpassing most PEC UV PDs. Furthermore, the PEC UV PDs have fast response, good stability, and underwater optical communication capability. This work offers more chances for the development of high-performance PEC UV PDs and demonstrates the potential application of ZnAl-LDH in underwater optoelectronic devices.