Ultraviolet Photodetectors Research Articles

Enhance the responsivity of self-driven ultraviolet photodetector by (Al,Ga)N nanowire/graphene/PVDF heterojunction with high stability.

Due to the low-power consumption, self-driven ultraviolet (UV) photodetectors have great potentials in a broad range of applications, such as optical communication, ozone monitoring, bio-medicine, and flame detection. In this Letter, it is pretty novel to enhance the photocurrent and responsivity of self-driven UV photodetectors by (Al,Ga)N nanowire/graphene/polyvinylidene fluoride (PVDF) heterojunction successfully. Compared to those of the photodetector with only nanowire/graphene heterojunction, it is found that both the photocurrent and responsivity of the photodetector with nanowire/graphene/PVDF heterojunction can be enhanced more than 100%. It is proposed that PVDF could maintain the internal gain by increasing the number of carrier cycles. Furthermore, this photodetector can also have a high detectivity of 5.3×1011 Jones and fast response speed under 310 nm illumination. After preserving for one month without any special protection, both photocurrent and responsivity of the photodetector with nanowire/graphene/PVDF heterojunction are demonstrated to be quite stable. Therefore, this work paves an effective way to improve the performance of photodetectors for their applications in the fields of next-generation optoelectronic devices.

Cost‐Effective and Flexible Scalable Fabrication of WO3 UV Photodetectors with Enhanced Performance via Integrated LIG Electrodes

AbstractThe emerging flexible device technologies have fascinated the modern optoelectronic industry owing to their invincible properties such as wearable, stretchable, smart, energy‐efficient, scalability, cost‐effective, and high performance. However, there is still room for improvements such as performance, reliability, and mass production. This research work fabricates laser‐induced graphene (LIG) interdigitated electrodes based on flexible UV photodetectors over polyimide substrate, using solution‐processed tungsten oxide (WO3) thin film as photoactive material. The best device performance is achieved through the optimization of laser power for the deposition of LIG, as well as a different solvent for WO3. The device shows excellent photoresponsivity, external quantum efficiency, and specific detectivity of 500 mA W−1, 164%, and 3.09 × 1012 Jones, respectively. Moreover, a fast response time, such as 0.3 ms for 375 nm light, is observed. This study offers a comprehensive elucidation of the intricate process through which photoelectrons are moved toward WO3 facilitated by the electric field present at the interface of the LIG and WO3.

Using thin-film transistor with thick oxygen-doped Si–Zn–Sn–O channel and patterned Pt/NiO capping layer to enhance ultraviolet light sensing performance

Improving the photodetection performance of thin-film transistor (TFT)-based UV photodetectors (UVPDs), using thick channel layers to promote photocurrent (I ph) or using thin channel layers to suppress dark current (I dark) is typically a trade-off. In this work, UVPDs based on oxygen-doped Si-Zn-Sn-O (SZTO) TFT with a stack of Pt/NiO capping layers (CLs) to release the trade-off between I dark and I ph are demonstrated. The Pt CL creates a wide depletion region in the channel layer to allow the use of thick channels, but still maintains low I dark, while the NiO CL forms a pn heterojunction to provide additional photogenerated carriers and enhance I ph under UV irradiation. Experimental results show that the proposed 95 nm-thick oxygen-doped SZTO TFT with a stack of Pt/NiO dual CLs exhibits an excellent photoresponsivity of 2026 A W−1 and photosensitivity of 9.3 × 107 A A−1, which are about 76× and 82.5× higher than a conventional 45 nm-thick SZTO TFT under 275 nm UV irradiation.

Effect of molar concentration on optoelectronic properties of NiO nanoparticles for p-n junction diode application

In this work, fine nickel oxide nanoparticles (NiO NPs) were successfully made utilizing a straightforward co-precipitation approach at low temperature. The effects of precursor concentration on the structural, optical, and electrical characteristics of NiO nanoparticles were investigated. All indexed diffraction peaks in XRD demonstrate the production of NiO with cubic structure. An increase in NiO crystallite size above 16.8 nm was observed when the precursor concentration exceeds 2 M, suggesting the presence of nanostructure in the final product. In FT-Raman spectra, the band centered at ∼ 500 cm–1 is due to Ni-O stretching (LO) mode, and two-magnon (2 M) scattering mode causes the band at 1514 cm–1. The synthesized product is composed of almost rod-shaped particles with a size range of 10–20 nm, according to FESEM pictures. The UV absorption studies showed a high absorption at the fundamental absorption edges originating at 332 nm, which gradually shifted to a lower energy region up to 400 nm with increasing precursor concentration, which means a reduction in bandgap values. The effect of precursor concentration associated with the electrical characteristics of the produced NiO nanoparticles has been investigated for the temperature range 30 to 130 °C. The I-V characterization was used to compute the different photo-diode parameters including n, ФB, Io, PS, R, QE, and D* . The remarkable high photosensitivity of 1100% and specific detectivity of 4.324 × 10−10 Jones for the diode evaluated at 120 mW/cm2 was observed in a 2 M fabricated diode. These findings imply that all the fabricated diodes are exceptionally light-sensitive and are well-suited for upcoming UV photodetector applications.

Wide Bandgap Semiconductors for Ultraviolet Photodetectors: Approaches, Applications, and Prospects.

Ultraviolet (UV) light, invisible to the human eye, possesses both benefits and risks. To harness its potential, UV photodetectors (PDs) have been engineered. These devices can convert UV photons into detectable signals, such as electrical impulses or visible light, enabling their application in diverse fields like environmental monitoring, healthcare, and aerospace. Wide bandgap semiconductors, with their high-efficiency UV light absorption and stable opto-electronic properties, stand out as ideal materials for UV PDs. This review comprehensively summarizes recent advancements in both traditional and emerging wide bandgap-based UV PDs, highlighting their roles in UV imaging, communication, and alarming. Moreover, it examines methods employed to enhance UV PD performance, delving into the advantages, challenges, and future research prospects in this area. By doing so, this review aims to spark innovation and guide the future development and application of UV PDs.

Hybrid Self-powered UV Photodetector with a Sandwich Structure of Asymmetric Interdigitated Electrodes

We present a novel ZnO/Au/Ti/p-GaN self-powered ultraviolet photodetector (UVPD) featuring a sandwich structure of asymmetric interdigitated electrodes. This unique design skillfully integrates the conventional vertically-structured ZnO/p-GaN UVPD, asymmetric Au/ZnO/Au UVPD,...

Power-free, filter-free and high-performance narrowband ZnO/BaTiO3/GaN heterojunction ultraviolet photodetector induced by synergetic plasmonic and ferroelectric effects

Narrowband ultraviolet photodetectors play a critical role in missile detection, flame monitoring, communication and other fields. Most commercial narrowband photodetectors, which are currently obtained by combining bandpass filters, face challenges...

An ultraviolet, self-powered, and large area photodetector based on a n-SnO2/p-spiro-OMeTAD organic–inorganic heterojunction

In this study, we fabricated an ultraviolet photodetector based on a n-SnO2/p-spiro-OMeTAD organic–inorganic heterojunction by spin-coating. Its optoelectronic properties and stability were studied.

The enhanced responsivity and response speed of SnO2 visible-blind transparent photodetectors via the SiO2 passivation layer.

Recently, transparent ultraviolet (UV) photodetectors have gained wide attention for their giant potential in integrated transparent electronics applications. SnO2 films as a common candidate for visible-blind transparent ultraviolet photodetectors have attracted increasing attention. In this work, high-performance visible-blind transparent UV photodetectors based on SnO2 thin film and a SiO2 passivation layer were successfully synthesized by the sol-gel spin coating method for the first time. The obtained SnO2/SiO2 hybrid device has a transmittance of nearly 80% in the visible band at 400-700 nm and demonstrates a high responsivity of 769 mA W-1 and a detection sensitivity of 1.24 × 1014 Jones under UV light illumination. The UV-C/UV-A rejection ratio is greater than 106, indicating that the device has good photo-selectivity. In addition, after the introdution of the SiO2 layer, the response speed is 2 times higher than that of pure SnO2. The presence of the SiO2 layer reduces the exposed area of SnO2, passivates the oxygen vacancies on the surface of SnO2 and inhibits the surface chemical adsorption. The above results provide a new perspective for improving the performance of SnO2 thin film for visible-blind transparent ultraviolet photodetectors.

Facile synthesis of photosensitive iron oxide nanorods and their application as UV photodetectors

Facile synthesis of photosensitive iron oxide nanorods and their application as UV photodetectors

The impact of interdigitated metal electrode on properties and performance of electrochemically reduced graphene oxide (ErGO) UV photodetector

The impact of interdigitated metal electrode on properties and performance of electrochemically reduced graphene oxide (ErGO) UV photodetector

Ferroelectrically modulated and enhanced photoresponse of a Ag/PZT/NSTO self-powered photodetector in the ultraviolet range

The photoelectric response of Ag/PZT/NSTO ultraviolet (UV) photodetectors is modulated through the manipulation of the polarization state of a PZT ultrathin film.

Self-assembled metal-oxo clusters for sensitive and low-powered ultraviolet photodetectors

Large-area and low-trap zirconium-oxo cluster (ZOC) flakes were synthesized by polymerization of ZOC subunits and used as an efficient photoactive component in UV photodetectors.

GaSe/<i>β</i>-Ga<sub>2</sub>O<sub>3</sub> heterojunction based self-powered solar-blind ultraviolet photoelectric detector

UV photodetectors have the advantages of high sensitivity and fast response speed. As an ultra-wide bandgap semiconductor, gallium oxide (Ga<sub>2</sub>O<sub>3</sub>) plays an extremely important role in detecting deep ultraviolet. It can form a typical type-II heterostructure with GaSe, promoting carrier separation and transport. In this work, Ga<sub>2</sub>O<sub>3</sub> epitaxial films are grown on sapphire substrates by plasma-assisted chemical vapor deposition (PECVD). The GaSe films and GaSe/<i>β</i>-Ga<sub>2</sub>O<sub>3</sub> heterojunction photodetectors are grown on gallium oxide films by Bridgeman technology. The detector has a good response to deep ultraviolet light, the dark current of the device is only 1.83 pA at 8 V, and the photocurrent reaches 6.5 nA at 254 nm. The UVC/Visible (254 nm/600 nm) has a high rejection ratio of about 354. At very small light intensities, the responsivity and detection can reach 1.49 mA/W and 6.65 × 10<sup>11</sup> Jones, respectively. At the same time, due to the photovoltaic effect formed by the space charge region at the junction interface, the detector exhibits self-powered supply performance at zero bias voltage, and the open-circuit voltage is 0.2 V. In addition, the detector has a very good sensitivity. The device can respond quickly, whether it is irradiated with different light intensities under constant voltage, or with different voltages under constant light intensity. It can respond within milliseconds under a bias voltage of 10 V. This work demonstrates the enormous potential of heterojunctions in photoelectric detection by analyzing the photophysical and interface physical issues involved in heterojunction photodetectors, and provides a possibility for detecting the deep ultraviolet of gallium oxide.

Ultrasensitive Narrowband Organic Phototransistor for Solar-Blind Ultraviolet Detection and Imaging

Solar-blind ultraviolet (SBUV) photodetectors has extensive applications in fields such as military operations, agriculture, and flame detection. However, most current ultraviolet detection is based on inorganic materials, and there is...

Performance optimization of self-powered ultraviolet and short-wavelength blue photodetectors based on ZnO/SrTiO3 heterojunctions by annealing treatment

In this study, self-powered photodetectors (PDs) sensitive to ultraviolet (UV) and short-wavelength blue (SWB) light were developed using a ZnO/SrTiO3 heterojunction, created through the magnetron sputtering technique.

Enhanced Responsivity of Solar Blind Ultraviolet Photodetector by PEALD Deposited Zn-Doped Ga2O3 Thin Films

Enhanced Responsivity of Solar Blind Ultraviolet Photodetector by PEALD Deposited Zn-Doped Ga₂O₃ Thin Films

Emerging lead-free all inorganic perovskite single crystals K7Bi3X16 (X = Cl, Br) toward photodetector application.

Lead-free inorganic perovskites have attracted intensive attention in the field of photodetectors owing to their high stability, non-toxicity, and remarkable photoelectric characteristics. Herein, we designed and developed a series of thus-far unreported lead-free all inorganic perovskite single crystals, K7Bi3X16 (X = Cl, Br). In particular, we resorted to cooling crystallization and intercalated K+ to inorganic Bi-Br and Bi-Cl frameworks as inorganic A-site cations, obtaining zero-dimensional (0D) K7Bi3X16 (X = Cl, Br) perovskite single crystals, which display suitable bandgaps, excellent electron mobility and low trap-state density, as analysed by experimental characterization and density functional theory (DFT) calculations. Accordingly, the vertical structure K7Bi3Br16 photodetector can achieve a fast ON/OFF switch under the irradiation of 395 nm light. When the light intensity is 5 mW cm-2 and the voltage is 3 V, the responsivity is calculated to be 0.052 mA W-1. The above characteristics make K7Bi3Br16 a promising material for fabricating ultraviolet photodetectors.

Study on the Performance of Graphene/GaN Ultraviolet Photodetectors Regulated Through Interface Engineering (Invited)

Study on the Performance of Graphene/GaN Ultraviolet Photodetectors Regulated Through Interface Engineering (Invited)

Self-Powered GaN-Based MSM Ultraviolet Photodetector With Asymmetrical Interdigitated Structure

Self-Powered GaN-Based MSM Ultraviolet Photodetector With Asymmetrical Interdigitated Structure