南方科技大学徐保民团队报道了小分子空穴传输材料用于26%效率倒置钙钛矿太阳能电池。相关研究成果发表在2024年12月18日出版的《美国化学会杂志》。

化学可改性的小分子空穴传输材料（HTMs）有望实现高效和可扩展的钙钛矿太阳能电池（PSCs）。与新兴的自组装单层相比，小分子HTMs在大面积沉积和长期操作稳定性方面更可靠。然而，目前倒置PSCs中的小分子HTMs缺乏平衡电荷传输能力，和界面兼容性的有效分子设计，导致功率转换效率（PCE）长期停滞在24.5%以下。

该文中，研究人员报告了HTM骨架和官能团的综合设计，该设计优化了一个简单的平面线性分子骨架，其迁移率超过7.1×10^-4cm² V^-1S^-1，并增强了其界面锚定能力。由于改进的表面性质和锚定效应，定制的HTMs增强了HTM/钙钛矿异质结处的界面接触，最大限度地减少了非辐射复合和输运损失，并实现了86.1%的高填充因子。

该工作克服了小分子HTMs，特别是大面积器件的持续效率瓶颈。因此，对于0.068 cm²的器件，所得PSCs的PCE为26.1%（25.7%经过认证），对于1.008 cm²的器件为24.7%（24.4%经过认证）。这代表了倒置PSCs中小分子HTMs的最高PCE。

附：英文原文

Title: Small-Molecule Hole Transport Materials for >26% Efficient Inverted Perovskite Solar Cells

Author: Jie Zeng, Zhixin Liu, Deng Wang, Jiawen Wu, Peide Zhu, Yuqi Bao, Xiaoyu Guo, Geping Qu, Bihua Hu, Xingzhu Wang, Yong Zhang, Lei Yan, Alex K.-Y. Jen, Baomin Xu

Issue&Volume: December 18, 2024

Abstract: Chemically modifiable small-molecule hole transport materials (HTMs) hold promise for achieving efficient and scalable perovskite solar cells (PSCs). Compared to emerging self-assembled monolayers, small-molecule HTMs are more reliable in terms of large-area deposition and long-term operational stability. However, current small-molecule HTMs in inverted PSCs lack efficient molecular designs that balance both the charge transport capability and interface compatibility, resulting in a long-standing stagnation of power conversion efficiency (PCE) below 24.5%. Here, we report the comprehensive design of HTMs’ backbone and functional groups, which optimizes a simple planar linear molecular backbone with a high mobility exceeding 7.1 × 10–4 cm2 V–1 S–1 and enhances its interface anchoring capability. Owing to the improved surface properties and anchoring effects, the tailored HTMs enhance the interface contact at the HTM/perovskite heterojunction, minimizing nonradiative recombination and transport loss and leading to a high fill factor of 86.1%. Our work has overcome the persistent efficiency bottleneck for small-molecule HTMs, particularly for large-area devices. Consequently, the resultant PSCs exhibit PCEs of 26.1% (25.7% certified) for a 0.068 cm2 device and 24.7% (24.4% certified) for a 1.008 cm2 device, representing the highest PCE for small-molecule HTMs in inverted PSCs.

DOI: 10.1021/jacs.4c13356

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c13356