High-Performance UV-Vis Broad-Spectra Photodetector Based on a β-Ga 2 O 3 /Au/MAPbBr 3 Sandwich Structure.

The UV-vis photodetector (PD), a detector that can simultaneously detect light in the ultraviolet region and the visible region, has a wide range of applications in military and civilian fields. Currently, it is very difficult to obtain good detection performance in the UV region (especially in the solar-blind range) like in the visible region with most UV-vis PDs. This severely affects the practical application of UV-vis broad-spectra PDs. Here, a simple sandwich structure PD (SSPD) composed of β-Ga 2 O 3 , Au electrodes, and the MAPbBr 3 perovskite is designed and fabricated to simultaneous enhance the detection performance in the UV and visible light regions. The β-Ga 2 O 3 /Au/MAPbBr 3 SSPD exhibits enhanced optoelectronic performance with high responsivities of 0.47 and 1.43 A W -1 at 240 and 520 nm under a bias of 6 voltage (V), respectively, which are 8.5 and 23 times than that of the metal-semiconductor-metal (MSM) structure MAPbBr 3 PD at 6 V, respectively. The enhanced performance was attributed to the effective suppression of carrier recombination due to the efficient interface charge separation in the device structure. In addition, the self-powered response characteristic is also realized by forming a type-II heterojunction between β-Ga 2 O 3 and MAPbBr 3 , which gives the β-Ga 2 O 3 /Au/MAPbBr 3 SSPD superior single-pixel photo-imaging ability without an external power supply. This work provides a simple and effective method for the preparation of high-performance self-powered imaging PDs in the UV-visible region.