题目：

Fast Organic Cation Exchange in Colloidal Perovskite Quantum Dots toward Functional Optoelectronic Applications

作者：

Chenyu Zhao^1,2, Claudio Cazorla³, Xuliang Zhang^1,2, Hehe Huang^1,2, Xinyu Zhao^1,2, Du Li^1,2, Junwei Shi¹, Qian Zhao⁵, Wanli Ma^1,4, and Jianyu Yuan^1,2*

单位：

¹Institute of Functional Nano & Soft Materials (FUNSOM)Soochow University, Suzhou, 215123, Jiangsu, P. R. China

²Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, P. R. China

³Departament de Física, Universitat Politècnica de Catalunya Campus Nord B4–B5, 08034 Barcelona (Spain)

⁴Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China

⁵School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China

摘要：

Colloidal quantum dots with lower surface ligand density are desired for preparing the active layer for photovoltaic, lighting, and other potential optoelectronic applications. In emerging perovskite quantum dots (PQDs), the diffusion of cations is thought to have a high energy barrier, relative to that of halide anions. Herein, we investigate the fast cross cation exchange approach in colloidal lead triiodide PQDs containing methylammonium (MA⁺) and formamidinium (FA⁺) organic cations, which exhibits a significantly lower exchange barrier than inorganic cesium (Cs⁺)-FA⁺and Cs⁺-MA⁺systems. First-principles calculations further suggest that the fast internal cation diffusion arises due to a lowering in structural distortions and the consequent decline in attractive cation–cation and cation–anion interactions in the presence of organic cation vacancies in mixed MA⁺-FA⁺PQDs. Combining both experimental and theoretical evidence, we propose a vacancy-assisted exchange model to understand the impact of structural features and intermolecular interaction in PQDs with fewer surface ligands. Finally, for a realistic outcome, the as-prepared mixed-cation PQDs display better photostability and can be directly applied for one-step coated photovoltaic and photodetector devices, achieving a high photovoltaic efficiency of 15.05% using MA_0.5FA_0.5PbI₃PQDs and more precisely tunable detective spectral response from visible to near-infrared regions.

影响因子：

16.383

分区情况：

一区

链接：

https://pubs.acs.org/doi/10.1021/jacs.3c14000