Tang Liting, Wang Xiaomin, Liu Xinxing, Zhang Junjun, Wang Shaoying, Zhao Yuqi, Gong Junbo, Li Jianmin, Xiao Xudong
Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072, China.
Center for Biomedical Optics and Photonics (CBOP) & College of Physics and Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems, Shenzhen University, Shenzhen, 518060, P. R. China.
Adv Sci (Weinh). 2022 Aug;9(23):e2201768. doi: 10.1002/advs.202201768. Epub 2022 Jun 8.
The interface between the perovskite layer and the hole transport layer (HTL) plays a vital role in hole extraction and electron blocking in perovskite solar cells (PSCs), and it is particularly susceptible to harmful defects. Surface passivation is an effective strategy for addressing the above concerns. However, because of its strong polarity, isopropyl alcohol (IPA) is used as a solvent in all of the surface treatment materials reported thus far, and it frequently damages the surface of perovskite. In this paper, a method is proposed for dissolving the passivation materials, for example, guanidine bromide (GABr), in mixed solvents (1:1) of IPA and toluene (TL), which can efficiently passivate interface and grain boundary defects by minimizing the IPA solubility of the perovskite surface. As a result, all the performance parameters Voc, Jsc, and FF are improved, and the power conversion efficiency (PCE) increased from 20.1 to 22.7%. Moreover, combining the PSCs with GABr post-treatment in mixed solvents with copper indium gallium selenide (CIGS) solar cells, a 4-terminal (4T) perovskite/CIGS tandem device is realized and a PCE of 25.5% is achieved. The mixed solvent passivation strategy demonstrated here, hopefully, will open new avenues for improving PSCs' efficiency and stability.
钙钛矿层与空穴传输层（HTL）之间的界面在钙钛矿太阳能电池（PSC）的空穴提取和电子阻挡中起着至关重要的作用，并且特别容易受到有害缺陷的影响。表面钝化是解决上述问题的有效策略。然而，由于其强极性，异丙醇（IPA）在迄今为止报道的所有表面处理材料中都用作溶剂，并且它经常会损坏钙钛矿的表面。本文提出了一种将钝化材料（例如溴化胍（GABr））溶解在IPA和甲苯（TL）的混合溶剂（1:1）中的方法，该方法可以通过最小化钙钛矿表面的IPA溶解度来有效地钝化界面和晶界缺陷。结果，所有性能参数Voc、Jsc和FF都得到了改善，功率转换效率（PCE）从20.1%提高到了22.7%。此外，将经过混合溶剂中GABr后处理的PSC与铜铟镓硒（CIGS）太阳能电池相结合，实现了一种4端（4T）钙钛矿/CIGS串联器件，并实现了25.5%的PCE。这里展示的混合溶剂钝化策略有望为提高PSC的效率和稳定性开辟新途径。
