High-performance Self-powered Ultraviolet Photodetectors Research Articles

Self-Powered Ultraviolet Photodetector with Superhigh Photoresponsivity (3.05 A/W) Based on the GaN/Sn:Ga2O3 pn Junction.

Ultraviolet (UV) radiation has a variety of impacts including the health of humans, the production of crops, and the lifetime of buildings. Based on the photovoltaic effect, self-powered UV photodetectors can measure and monitor UV radiation without any power consumption. However, the current low photoelectric performance of these detectors has hindered their practical use. In our study, a super-high-performance self-powered UV photodetector based on a GaN/Sn:Ga2O3 pn junction was generated by depositing a Sn-doped n-type Ga2O3 thin film onto a p-type GaN thick film. The responsivity at 254 nm reached up to 3.05 A/W without a power supply and had a high UV/visible rejection ratio of R254nm/ R400nm = 5.9 × 103 and an ideal detectivity at 1.69 × 1013 cm·Hz1/2·W-1, which is well beyond the level of previous self-powered UV photodetectors. Moreover, our device also has a low dark current (1.8 × 10-11A), a high Iphoto/ Idark ratio (∼104), and a fast photoresponse time of 18 ms without bias. These outstanding performance results are attributed to the rapid separation of photogenerated electron-hole pairs driven by a high built-in electric field in the interface depletion region of the GaN/Sn:Ga2O3 pn junction. Our results provide an improved and easy route to constructing high-performance self-powered UV photodetectors that can potentially replace traditional high-energy-consuming UV detection systems.

High performance self-powered ultraviolet photodetectors based on electrospun gallium nitride nanowires

Generally, one-dimensional nanowires (NWs) show higher electron mobility than their nanoparticles, due to that they can provide a direct transport channel for photogenerated carriers of the assembled devices. In this work, gallium nitride (GaN) NWs prepared by electrospinning technique were applied into as a substitute for GaN particles (GaN-P) in GaN-based photoelectrochemical (PEC) self-powered ultraviolet (UV) photodetectors. Results show the UV photodetectors based on GaN-NWs can exhibit a rapid response (tr = 0.28 s, td = 0.25 s), which is highly improved compared to that of the GaN-P based device (tr = 0.37 s, td = 0.3 s). Moreover, the GaN-NW UV photodetectors also perform high reproducibility and stability (testing for 80 days). This research indicates that the GaN-NW-based photoanodes will further widen the advancements for PEC-type self-powered UV photodetectors.

A novel high-performance self-powered ultraviolet photodetector: Concept, analytical modeling and analysis

In this paper, a new MSM-UV-photodetector (PD) based on dual wide band-gap material (DM) engineering aspect is proposed to achieve high-performance self-powered device. Comprehensive analytical models for the proposed sensor photocurrent and the device properties are developed incorporating the impact of DM aspect on the device photoelectrical behavior. The obtained results are validated with the numerical data using commercial TCAD software. Our investigation demonstrates that the adopted design amendment modulates the electric field in the device, which provides the possibility to drive appropriate photo-generated carriers without an external applied voltage. This phenomenon suggests achieving the dual role of effective carriers’ separation and an efficient reduce of the dark current. Moreover, a new hybrid approach based on analytical modeling and Particle Swarm Optimization (PSO) is proposed to achieve improved photoelectric behavior at zero bias that can ensure favorable self-powered MSM-based UV-PD. It is found that the proposed design methodology has succeeded in identifying the optimized design that offers a self-powered device with high-responsivity (98 mA/W) and superior ION/IOFF ratio (480 dB). These results make the optimized MSM-UV-DM-PD suitable for providing low cost self-powered devices for high-performance optical communication and monitoring applications.

Surface photo-charge effect in doped-ZnO nanorods for high-performance self-powered ultraviolet photodetectors.

The unique photo-charge characteristics of chlorine-doped zinc oxide nanorods (Cl-ZnO NRs) are explored for the first time in ultraviolet (UV) photodetector (PD) that offers an outstanding self-powered photoresponse towards low UV illumination signals. A self-powered Cl-ZnO NRs PD exhibits superior photon detection speed of the order of a few ms with high sensitivity and photoelasticity. Therefore, the presented PD opens up a novel route to fabricate highly efficient self-powered PDs on a large scale without employing complex multilayer systems.

Coupling of photoelectric and triboelectric effects as an effective approach for PZT-based high-performance self-powered ultraviolet photodetector

A high-performance self-powered UV photodetector (UV-SPPD) using a PZT film was fabricated and characterized. It has a dual sensing mechanism that relies on the joint properties of a photoelectric effect and a triboelectric effect on the surface of the ferroelectric material. The UV-SPPD exhibits excellent responsivity (15mAW−1), large detectivity (2×1010cmHz−1/2 W−1), a fast photo response time (<50ms), and good stability and repeatability. This work creates new opportunities for designing high-performance self-powered UV photodetectors and other tribotronic devices.

Energy-Efficient Hydrogenated Zinc Oxide Nanoflakes for High-Performance Self-Powered Ultraviolet Photodetector

Light absorption efficiency and doping induced charge carrier density play a vital role in self-powered optoelectronic devices. Unique vanadium-doped zinc oxide nanoflake array (VZnO NFs) is fabricated for self-powered ultraviolet (UV) photodetection. The light harvesting efficiency drastically improved from 84% in ZnO NRs to 98% in VZnO NFs. Moreover, the hydrogenation of as-synthesized VZnO (H:VZnO) NFs displayed an outstanding increase in response current as compared to pristine structures. The H:VZnO NFs device presents an extraordinary photoelastic behavior with faster photodetection speed in the order of ms under a low UV illumination signal. Excellent responsivity and external quantum efficiency with larger value of specific detectivity of H:VZnO NFs device promises an outstanding sensitivity for UV signal and self-powered high-performance visible-blind photodetector.