摘要
As a lead-free perovskite,CsBi3I10 has attracted significant attention because of its high thermal tolerance and long electron diffusion length.Solution-processed high-performance CsBi3I10 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 CsBi3I10 perovskite films.Compared with traditionally spin-coated CsBi3I10 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 CsBi3I10 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.
因具有较高的耐热性和较长的电子扩散长度,无铅钙钛矿Cs Bi3I10备受关注.然而,由于二维结构Cs Bi3I(10)钙钛矿的表面极其粗糙且存在大量针孔,导致Cs Bi3I10钙钛矿器件性能不高.本文报道了一种利用空间限域生长(SCG)获得高平滑度、高结晶度和致密CsBi3I10钙钛矿薄膜的方法.相对于传统旋涂法制备的探测器,采用SCG方法获得的金属-半导体-金属结构Cs Bi3I10光电探测器(PDs)具有更高的光电流、更低的暗电流,以及更大的开/关比.此外,在长时间测试下,未封装的CsBi3I10钙钛矿PDs的光电流没有衰减;在空气中储存30天后,器件的性能也没有明显的退化,表现出了超高的稳定性.研究表明空间限域生长方法为制备高质量无铅钙钛矿开辟了一条新途径,有望在发光二极管、太阳能电池等领域得到应用.
基金
the National Natural Science Foundation of China(51972101 and 11874143)
the Natural Science Foundation of Hubei Province(2019CFB508)
Wuhan Yellow Crane Talent Program(2017-02)。
