王穗东教授与徐建龙副教授合作在Adv. Funct. Mater. 上发表论文

题目：

Probing into Reverse Bias Dark Current in Perovskite Photodiodes: Critical Role of Surface Defects

作者：

Zhao-Yang Yin¹, Yang Chen¹, Yang-Yang Zhang¹, Yu Yuan¹, Qian Yang¹, Ya-Nan Zhong¹, Xu Gao¹, Jing Xiao², Zhao-Kui Wang¹, Jian-Long Xu¹*, and Sui-Dong Wang^1,3*

单位：

¹Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices Soochow University, Suzhou Jiangsu 215123, P. R. China.

²College of Physics and Electronic Engineering, Taishan University, Taian Shandong 271000, P. R. China.

³Macao Institute of Materials Science and Engineering (MIMSE), MUST-SUDA Joint Research Center for Advanced Functional Materials, Macau University of Science and Technology, Taipa Macao 999078, P. R. China.

摘要：

Minimizing reverse bias dark current density (J_dark) while retaining high external quantum efficiency is crucial for promising applications of perovskite photodiodes, and it remains challenging to elucidate the ultimate origin of J_dark. It is demonstrated in this study that the surface defects induced by iodine vacancies are the main cause of J_dark in perovskite photodiodes. In a targeted way, the surface defects are thoroughly passivated through a simple treatment with butylamine hydroiodide to form ultrathin 2D perovskite on its 3D bulk. In the passivated perovskite photodiodes, J_dark as low as 3.78 × 10^-10 A cm^-2 at -0.1 V is achieved, and the photoresponse is also enhanced, especially at low light intensities. A combination of the two improvements realizes high specific detectivity up to 1.46 × 10¹² Jones in the devices. It is clarified that the trap states induced by the surface defects can not only raise the generation-recombination current density associated with the Shockley–Read–Hall mechanisms in the dark (increasing J_dark), but also provide additional carrier recombination paths under light illumination (decreasing photocurrent). The critical role of surface defects on J_dark of perovskite photodiodes suggests that making trap-free perovskite thin films, for example, by fine preparation and/or surface engineering, is a top priority for high-performance perovskite photodiodes.

影响因子：

19.924

分区情况：

一区

链接：

https://onlinelibrary.wiley.com/doi/10.1002/adfm.202302199