Ultra-low dark current and high sensitivity lead-free perovskite–like photodetector realized by anti-solvent optimization Cs3Bi2I9 amorphous film

Abstract

Compared with lead halide perovskite, bismuth-based perovskite has lower toxicity and air stability, demonstrating enormous potential for application, among them, Cs3Bi2I9 materials has been researched as an alternative to lead-based perovskite for application of optoelectronic devices. It is crucial for the realization of high-performance photodetectors which need high-quality perovskite thin films. Here, we prepared a lead-free, all-inorganic, Cs3Bi2I9 perovskite-like amorphous films by spin coating method, and diethyl ether was added as an anti-solvent at different times of spin-coating. The results show that the homogeneous and dense Cs3Bi2I9 amorphous films can be obtained by adding anti-solvent at 14seconds. Furthermore, Cs3Bi2I9 perovskite-like UV photodetector achieved extremely low dark current around ~pA range, high sensitivity of 1.10×104 was fabricated. Our research shows that the preparation of Cs3Bi2I9 amorphous films by the simple antisolvent-assisted spin-coating method are very promising for optoelectronic device.