美国加州大学洛杉机分校Yang, Yang团队报道了钙钛矿型光伏材料的稳定限制的异质界面。相关研究成果发表在2022年3月15日出版的《自然》。

光电器件由不同半导体材料之间形成的异质界面组成。接触半导体之间的相对能级排列决定了异质界面电荷注入和萃取动力学。对于钙钛矿太阳能电池（PSCs），顶部钙钛矿表面和电荷传输材料（CTM）之间的异质界面通常进行缺陷钝化处理，以提高PSC的稳定性和性能。然而，这种表面处理也会影响异质界面的能量学。

该文中，研究表明，表面处理可能会导致负功函数偏移（即更多的n型），这会激活卤化物迁移，从而加剧PSC不稳定性。因此，尽管表面钝化有好处，但这种有害的副作用限制了以这些方式处理的PSC可获得的最大稳定性改善。这种有利和不利影响之间的权衡应该可以引导通过表面处理改善PSC稳定性的进一步工作。

附：英文原文

Title: Stability-limiting heterointerfaces of perovskite photovoltaics

Author: Tan, Shaun, Huang, Tianyi, Yavuz, Ilhan, Wang, Rui, Yoon, Tae Woong, Xu, Mingjie, Xing, Qiyu, Park, Keonwoo, Lee, Do-Kyoung, Chen, Chung-Hao, Zheng, Ran, Yoon, Taegeun, Zhao, Yepin, Wang, Hao-Cheng, Meng, Dong, Xue, Jingjing, Song, Young Jae, Pan, Xiaoqing, Park, Nam-Gyu, Lee, Jin-Wook, Yang, Yang

Issue&Volume: 2022-03-15

Abstract: Optoelectronic devices consist of heterointerfaces formed between dissimilar semiconducting materials. The relative energy level alignment between contacting semiconductors determinately affects the heterointerface charge injection and extraction dynamics. For perovskite solar cells (PSCs), the heterointerface between the top perovskite surface and a charge-transporting material (CTM) is often treated for defect passivation1–4 to improve PSC stability and performance. However, such surface treatments could also affect the heterointerface energetics.1 Here we show that surface treatments may induce a negative work function shift (i.e. more n-type), which activates halide migration to aggravate PSC instability. Therefore, despite the beneficial effects of surface passivation, this detrimental side effect limits the maximum stability improvement attainable for PSCs treated in these ways. This trade-off between the beneficial and detrimental effects should guide further work on improving PSC stability via surface treatments.

DOI: 10.1038/s41586-022-04604-5

Source: https://www.nature.com/articles/s41586-022-04604-5