香港理工大学严锋小组的一项最新研究，提出了基于噻吩基铵的高效2D/3D卤化锡钙钛矿太阳能电池的A-Site工程化。这一研究成果发表在2024年10月15日出版的国际学术期刊《德国应用化学》上。

据介绍，锡卤化钙钛矿由于其低毒性和理想的带隙能量，而成为无铅钙钛矿太阳能电池（PSCs）最有前途的候选材料。在锡基PSCs （TPSCs）中引入2D/3D混合钙钛矿相，已被证明是提高器件效率和稳定性的最有效方法。然而，二维钙钛矿相通常表现出相对较低的载流子迁移率，这将不利于载流子在器件中的转移。

在这项工作中，该课题组将噻吩基阳离子2-(thiophen-3-yl)ethan-1-aminium （3-TEA）作为间隔物，在无铅钙钛矿太阳能电池（TPSCs）中形成了一种新的2D钙钛矿相，与其他阳离子如2-(thiophen-2-yl)ethan-1-aminium （2-TEA）和苯基2-phenylethan-1-aminium （PEA）相比较，它显示出最有希望的性能增强效果。

理论计算表明，3-TEA可以使[SnI₆]^4-八面体层的晶体排列最紧凑，从而在2D相中获得最低的空穴有效质量和形成能。这种效应通过促进二维相内更有效的载流子转移，显著提高了器件的效率和稳定性。这些发现表明，噻吩基二维钙钛矿非常适合用于高性能TPSCs。

附：英文原文

Title: A-Site Engineering with Thiophene-Based Ammonium for High-Efficiency 2D/3D Tin Halide Perovskite Solar Cells

Author: Guitao Feng, Hok-Leung Loi, Tianyue Wang, Wenqiu Deng, Zhiqiang Guan, Qi Wei, Jiandong He, Mingjie Li, Chun-Sing Lee, Jizheng Wang, Qichun Zhang, Feng Yan

Issue&Volume: 2024-10-15

Abstract: TTin halide perovskites are the most promising candidate materials for lead-free perovskite solar cells (PSCs) thanks to their low toxicity and ideal bandgap energies. The introduction of 2D/3D mixed perovskite phases in tin-based PSCs (TPSCs) has proven to be the most effective approach to improving device efficiency and stability. However, a 2D perovskite phase normally shows relatively low carrier mobility, which will be unfavorable for carrier transfer in the devices. In this work, we used a thiophene-based cation 2-(thiophen-3-yl)ethan-1-aminium (3-TEA) as a spacer to form a novel 2D perovskite phase in TPSCs, which shows the most promising effect on the performance enhancement in comparison with other cations like 2-(thiophen-2-yl)ethan-1-aminium (2-TEA) and benzene-based 2-phenylethan-1-aminium (PEA). Theoretical calculations reveal that 3-TEA enables the most compact crystal packing of [SnI6]4- octahedral layers, resulting in the lowest hole effective mass and formation energy in the 2D phase. This effect significantly enhances device efficiency and stability by facilitating more efficient carrier transfer within the 2D phase. These findings indicate that thiophene-based 2D perovskites are well-suited for high-performance TPSCs.

DOI: 10.1002/anie.202413584

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202413584