Research On The Preparation Of All-inorganic Perovskite Photodetectors By Anti-solvent Metho

Based on the research basis of organic and inorganic hybrid perovskite optoelectronic devices,the perovskite Cs₃Bi₂I₉contains no lead ions,non-toxic and environmentally friendly and has good stability.Most of the reported Cs₃Bi₂I₉-based photodetectors use Cs₃Bi₂I₉single crystal films.Although the photoelectric performance is excellent,the preparation process is relatively complex.After modifying the substrate surface with OTS,A uniform flat Cs₃Bi₂I₉amorphous film was obtained by using chlorobenzyl and ether and one-step spin coating method.and a high performance planar photoconductivity photodetector with a light/dark current ratio up to 10⁴was prepared.In this paper,chlorobenzene was selected as the antisolvent and the addition time of antisolvent was further optimized.A thin film with a dense and flat surface was obtained.On this basis,the forked gold electrode was deposited to explore the photoelectric performance of the device.The research results showed that the photoelectric performance parameters of the photodetector prepared by using chlorobenzene antisolvent,such as light/dark current ratio（P）,light responsiveness（R）,specific detection rate（D*）,etc.were significantly improved.The specific detection rate（D*）reached 2.12×10¹¹Jones.This indicates that amorphous Cs₃Bi₂I₉thin film photodetectors prepared with chlorobenzene antisolvent have great application potential.The effect of ether as antisolvent on the performance of Cs₃Bi₂I₉photodetector was further discussed.The results show that the P value of the device with ether antisolvent added at 14 s is increased by 3 orders of magnitude,the R is increased by about 100 times,and the D*reaches 9.00×10¹¹Jones.The photoelectric performance of the device is more optimized than that of chlorobenzene antisolvent.The results show that amorphous Cs₃Bi₂I₉thin film photodetector prepared by ether reverse-solvent method is a kind of photodetector with excellent performance.This study provides important theoretical and experimental data support for the large-scale application of all inorganic perovskite-like photodetectors in the future.