Photoelectrochemical Self-Powered Solar-Blind Photodetectors Based on Ga₂O₃ Nanorod Array/Electrolyte Solid/Liquid Heterojunctions with a Large Separation Interface of Photogenerated Carriers

Abstract

Solar-blind photodetectors have been widely developed because of their great potential application in biological analysis, ultraviolet communication, and so on. Photodetectors constructed by vertically aligned nanorod arrays (NRAs), have attracted intensive interest recently owing to the virtues of low light reflectivity and rapid electron transport. However, limited by the insufficient contact between the upper electrode and NRAs because of uneven NRAs, photogenerated carriers cannot be effectively separated and transferred. In this work, a novel photoelectrochemical (PEC) type self-powered solar-blind photodetectors constructed in the form of Ga2O3 NRAs/electrolyte solid/liquid heterojunction with a large photogenerated carrier separation interface has been fabricated, β-Ga2O3 NRAs PEC photodetector shows a photoresponsivity of 3.81 mA/W at a bias voltage of 0 V under the 254 nm light illumination with the light intensity of 2.8 mW/cm2, thus yielding a I photo/I dark ratio of 28.97 and an external quantum efficiency of 1.86%. Our results provide a novel device structure of solar-blind photodetector with high efficient deep-ultraviolet photodetection and low power consumption.

Highly Uniform, Self‐Assembled AlGaN Nanowires for Self‐Powered Solar‐Blind Photodetector with Fast‐Response Speed and High Responsivity

“…For a better comparison of the solar‐blind photodetection ability, Figure 4d plots the device performance of the newly designed PEC PDs in this work and recently reported self‐powered solar‐blind PEC PDs with nanostructure photoelectrodes based on wide bandgap oxides and sulfides. [ 12,34–36 ] Obviously, our proposed AlGaN:Ru NW PEC PD shows ever‐reported fastest photoresponse speed and highest responsivity, revealing the great potential of such device architectures in the field of the high‐efficiency solar‐blind PEC photodetection. Moreover, the device performance of AlGaN:Ru NW PEC PDs depends not only on the excitation and transport of carriers within the semiconductor itself, but also on the diffusion of ions in the aqueous environment, which provide us a new method to modulate the photodetection performance to meet desired requirements.…”

“…Thereafter, the redox molecules, which diffuse through the H 2 SO 4 electrolyte to the surface of the Pt counter electrode, are reduced to hydroxide ions with the help of electrons re-entered from the external circuit (e − + OH * → OH − ), completing the current loop. [34][35][36] The Ag/AgCl electrode serves as the reference electrode which has a stable and well-known electrode potential. Its only role is to act as a reference in measuring and controlling the working electrode's potential and at no point does it pass any current and undergo chemical reactions.…”

A robust 3D self-powered photoelectrochemical type photodetector based on MoSe2 nanoflower

“…The change of photocurrent density from 0V to 1V may be due to the large speci c surface area of MoSe 2 nano ower reduces the scattering of light and increases the refraction of light, which leads to the full absorption of light, which is also good for the increase of photocurrent. In addition, the large speci c surface area and high light absorption are su cient to achieve charge exchange between the holes of MoSe 2 surface with the OH -(h + + OH -= OH•) in the electrolyte [41].…”

ALD oxygen vacancy-rich amorphous Ga2O3 on three-dimensional urchin-like ZnO arrays for high-performance self-powered solar-blind photodetectors

“…Alternatively, photoelectrochemical (PEC) type photodetectors, which can be fabricated by a low-cost lithography-free process without a top metal electrode, while enabling perfect contact between the electrode and electrolyte, and offering sufficient separation interfaces for photogenerated carriers, are promising in sustainable optoelectronic systems. 10–12…”

“…25,26 In a bid to improve the device efficiency, 3D nanostructured construction can be introduced to reinforce the performance of photo-responsive materials to perfectly match the application scenario of PEC-type photodetectors. 12…”