基于绿色反溶剂工程的钙钛矿结晶过程调控及其机理  

Regulation of Perovskite Crystallization Process and Its Mechanism Based on Green Anti-solvent Engineering

作　　者：刘志军[1] 杨平[1] 亢天利 刘凤霞[1] 许晓飞[1] 李志义[1] 魏炜[1] LIU Zhijun;YANG Ping;KANG Tianli;LIU Fengxia;XU Xiaofei;LI Zhiyi;WEI Wei(R&D Institute of Fluid and Powder Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学流体与粉体工程研究设计所,辽宁大连116024

出　　处：《发光学报》2025年第1期70-80,共11页Chinese Journal of Luminescence

摘　　要：乙酸乙酯(Ethyl acetate,EA)常作为绿色反溶剂来制备钙钛矿薄膜,但高极性导致萃取速率过快,使晶体的成核和结晶过程难以控制。本文通过向EA中添加正己烷(n-hexane,Hex)调节反溶剂萃取速率,进而控制溶液过饱和度使晶体的成核和生长过程达到动态平衡;同时使用Materials Studio软件对溶剂-反溶剂体系进行分子动力学模拟,定量计算其相互作用能。实验表明,60%N-Hex(反溶剂中Hex所占摩尔分数为60%)混合反溶剂制备的钙钛矿薄膜平均晶粒尺寸为249 nm,比纯EA和纯Hex制备薄膜分别提升17%和71%;载流子寿命为225 ns,比纯EA和纯Hex制备薄膜分别提升27%和45%;同时该薄膜(110)晶面优先取向。本实验的分子动力学计算结果表明,当溶剂-反溶剂相互作用力为1385 kJ/mol时,得到最佳钙钛矿薄膜。Ethyl acetate(EA)is commonly used as a green anti-solvent for the preparation of perovskite films.However,its high polarity leads to an excessively fast extraction rate,which complicates the control of the nucleation and crystallization processes.In this study,we adjusted the anti-solvent extraction rate by adding n-hexane(Hex)to EA,which allowed to control the solution’s supersaturation and achieve a dynamic equilibrium in the nucleation and growth processes of the crystals.Additionally,molecular dynamics simulation of the solvent and anti-solvent system was carried out using Materials Studio software,and the interaction energy of the solvent and anti-solvent system was quantitatively calculated.The experimental results show that the average grain size of the perovskite film prepared by 60%N-Hex(i.e.,60%molar percentage of Hex in the anti-solvent)is 249 nm,which is 17%and 71%larger than films prepared with pure EA and pure Hex,respectively.The carrier lifetime was 225 ns,which is 27%and 45%longer than that of films made with pure EA and pure Hex,respectively.Furthermore,the crystal plane of this thin film(110)is the dominant crystal plane.The molecular dynamics calculations of this experiment suggest that the best perovskite film was obtained when the solvent and anti-solvent interaction energy is 1385 kJ/mol.

关 键 词：钙钛矿 绿色 反溶剂工程 分子动力学 

分 类 号：O482.31[理学—固体物理]