A Novel Self‐Powered and High Switching Ratio UV–vis Photodetector Based on Multilayer Bi2O3/In2O3 Heterojunction

Metal oxides have attracted more and more attention as common candidates for photodetectors. However, most metal oxide detectors are limited by the shortcomings such as wide bandgap, high manufacturing cost, and slow response speed. Herein, a UV–vis Bi 2 O 3 /In 2 O 3 heterojunction photodetector is successfully achieved by a two‐step spin coating method. Based on X‐ray diffraction and scanning electron microscopy measurements, the crystal form and morphology of the Bi 2 O 3 /In 2 O 3 heterojunction are determined. The UV–vis absorption spectroscopy and UV photoelectron spectroscopy tests indicate that the Bi 2 O 3 /In 2 O 3 forms a type II heterojunction and the successful combination of the two enhances the light detection capability of the photodetector. Additionally, the Bi 2 O 3 /In 2 O 3 heterojunction photodetector possesses a self‐powered characteristic with a responsivity, detectivity, and response time of 0.66 mA W −1 , 5.78 × 10 10 Jones, and 1.90 s, respectively. The above results demonstrate that the multilayer Bi 2 O 3 /In 2 O 3 heterojunction is a promising UV–vis broadband photodetector.