Space-confined growth of high-quality CsBi3I10 lead-free perovskite film for near-infrared photodetectors with high sensitivity and stability

• Published in: Science China materials 2021-02, Vol.64 (2), p.393-399
• Main Authors: Liu, Ronghuan, Zhou, Hai, Wang, Rui, Wu, Dingjun, Pan, Xiyan, Pan, Guangdong, Wang, Hao
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Chemistry/Food Science; Chlorobenzene; Dark current; Diffusion length; Electron diffusion; Extreme values; Lead free; Light emitting diodes; Materials Science; Perovskites; Photoelectric effect; Photoelectric emission; Photometers; Photovoltaic cells; Pinholes; Polystyrene resins; Smoothness; Solar cells; Spin coating; Stability; Surface roughness; Toluene
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-020-1447-3

As a lead-free perovskite, CsBi 3 I 10 has attracted significant attention because of its high thermal tolerance and long electron diffusion length. Solution-processed high-performance CsBi 3 I 10 perovskite devices, however, are hindered by the formation of a two-dimensional structure, which results in an extremely high surface roughness and many pinholes. In this paper, we reported a space-confined growth (SCG) method using a single-layer polystyrene (PS) sphere template to obtain high-smoothness, high-crystallinity, and dense CsBi 3 I 10 perovskite films. Compared with traditionally spin-coated CsBi 3 I 10 photodetectors (PDs), the metal-semiconductor-metal PDs made by SCG showed a higher photocurrent, a lower dark current, and a bigger on/off ratio. In addition, the photocurrent of our unencapsulated CsBi 3 I 10 perovskite PDs was not attenuated under long-time illumination. In addition, when the device was stored in air for 30 d, its performance also showed no degradation, demonstrating ultra-high stability. Furthermore, the synthesis was free of antisolvents, such as chlorobenzene and toluene, which is beneficial for the environmentally friendly assembly of the devices. Our strategy opens up a new way to prepare high-quality lead-free perovskite, which may be useful for applications in light-emitting diodes and solar cells.