High-performance self-powered ultraviolet Ti3C2Tx/GaN Schottky photodiode with an interdigitated electrode

Ultraviolet photodetectors (UV-PDs) with high sensitivity and fast optical response have become an important part of modern optoelectronic information transmission and communication systems. In this paper, a high-performance self-powered titanium carbide (${{\rm Ti}_{3}}{\rm C_2}{\rm T_x}$)/gallium nitride (GaN) Schottky UV-PD with an interdigitated electrode was developed. A Schottky-contacted ${{\rm Ti}_{3}}{\rm C_2}{\rm T_x}$ interdigitated electrode was successfully fabricated on GaN substrates using a spray coating method. The as-prepared ${{\rm Ti}_{3}}{\rm C_2}{\rm T_x}/{\rm GaN}$ UV-PD exhibits excellent optoelectronic properties. Under zero bias and weak UV illumination (${48}\;\unicode{x00B5} {{\rm W/cm}^{2}}$), the device demonstrates an ultra-low dark current (${2.818} \times {{10}^{- {10}}}\;{\rm A}$) and a fast response speed (${{\rm t}_{\rm r}} = {170}\;\unicode{x00B5} {{\rm s/t}_{\rm f}} = {210}\;\unicode{x00B5} {\rm s}$); the responsivity and detectivity could reach 120.78 mA/W and ${1.272} \times {{10}^{{12}}}$ Jones, respectively. Furthermore, to demonstrate the feasibility of practical application, the device was applied in a UV point-of-view imaging system and high-quality images were successfully obtained under low-light conditions. This work presents an effective approach in developing high-performance UV-PDs for optical imaging applications.