Boosting photoresponses in a SnO2 microwire heterojunction ultraviolet self-biased photodetector through tailoring heterointerface

The large bandgap SnO2 exhibits outstanding ultraviolet light absorption and excellent semiconductor properties, thus making it a promising candidate to developing photodiodes in the short wavelengths. Herein, a performance -boosting self -driven ultraviolet photodetector based on a SnO2 microwire heterojunction was reported. Through a rational structure design via MgO electron -blocking layer and Ag nanowires (AgNWs), the optimized photodiode reveals a fantastic photovoltaic effect with a maximum open -circuit voltage of about 1.78 V. Upon 345 nm light illumination via 0.57 mW/cm2 at 0 V bias, the maximum values of On/Off ratio, photoresponsivity, detectivity, external quantum efficiency were evaluated to approximately 3.3 x 105, 231.04 mA/W, 2.08 x 1013 Jones, and 78.33%, respectively. The photodiode shows an ultrafast response speed with a rising/decaying times of 989.0 mu s/2.0 ms. The comprehensive performance exceeds most reported state-of-theart SnO2-related self -powered photodetectors. In the optimized design, inserting a MgO tunneling nanolayer, which is associated with surface -modified AgNWs, enables the SnO2 sample featuring as a predominant ultraviolet absorber, thus achieving efficient modification of energy band alignment, charge carrier transport, specific ultraviolet spectrum selectivity, etc. Profit from the fascinating performances, the n-AgNWs@SnO2 MW/MgO/p-GaN heterojunction photodiode working as a single pixel unit fulfills high -definition imaging. The rational design proposed in this study, which enables to boost properties of optoelectronic devices, is definitely a very promising scheme to realistic applications in future.