Yeh Chia-Hsun, Cheng Wen-Yu, Chou Tai-Che, Liu Yi-Chun, Chang Chia-Wei, Chen Yu-Sheng, Wang Chih-Hsing, Weng Shih-Chang, Sharp Ian D, Chou Pi-Tai, Jiang Chang-Ming
Department of Chemistry, National Taiwan University 10617 Taipei Taiwan
Walter Schottky Institute, Technical University of Munich 85748 Garching Germany
Nanoscale Adv. 2025 Jul 28. doi: 10.1039/d5na00599j.
Hybrid organic-inorganic halide perovskites are celebrated for their exceptional optoelectronic properties and facile fabrication processes, making them prime candidates for next-generation photovoltaic and optoelectronic devices. By incorporating larger organic cations at the A-site, a novel class of '3D hollow perovskites' has been developed, exhibiting enhanced stability and tunable optoelectronic properties. This study systematically explores the structural, phase transition, and photophysical characteristics of {en}MAPbI thin films with varying ethylenediammonium (en) content. The incorporation of less polar en expands the perovskite unit cell, prolongs carrier lifetimes, and disrupts MA dipole-dipole interactions, thereby lowering the tetragonal-to-orthorhombic phase transition temperature. Temperature-dependent photoluminescence studies reveal that en incorporation reduces the intensity and Stokes shift of self-trapped exciton emission at low temperatures, which are attributed to the diminished collective rotational dynamics of MA cations. These findings underscore the critical role of A-site cation dynamics in modulating phase stability and excitonic behaviour within hybrid halide perovskites, deepening our understanding of the interplay between organic cations and the inorganic framework and highlighting the potential of 3D hollow perovskites for stable and tunable optoelectronic applications.
有机-无机杂化卤化物钙钛矿因其优异的光电性能和简便的制备工艺而备受赞誉，使其成为下一代光伏和光电器件的主要候选材料。通过在A位引入更大的有机阳离子，开发了一类新型的“3D中空钙钛矿”，具有增强的稳定性和可调的光电性能。本研究系统地探索了不同乙二胺（en）含量的{en}MAPbI薄膜的结构、相变和光物理特性。引入极性较小的en会扩大钙钛矿晶胞，延长载流子寿命，并破坏MA偶极-偶极相互作用，从而降低四方相到正交相的转变温度。温度相关的光致发光研究表明，引入en会降低低温下自陷激子发射的强度和斯托克斯位移，这归因于MA阳离子集体旋转动力学的减弱。这些发现强调了A位阳离子动力学在调节杂化卤化物钙钛矿内的相稳定性和激子行为中的关键作用，加深了我们对有机阳离子与无机框架之间相互作用的理解，并突出了3D中空钙钛矿在稳定和可调光电子应用中的潜力。
