Hamada Kengo, Tanaka Ryo, Kamarudin Muhammad Akmal, Shen Qing, Iikubo Satoshi, Minemoto Takashi, Yoshino Kenji, Toyoda Taro, Ma Tingli, Kang Dong-Won, Hayase Shuzi
Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu-shi, Fukuoka-ken 808-0196, Japan.
Faculty of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.
ACS Appl Mater Interfaces. 2020 Apr 15;12(15):17776-17782. doi: 10.1021/acsami.0c01411. Epub 2020 Apr 4.
Research on tin-lead (SnPb) perovskite solar cells (PSCs) has gained popularity in recent years because of their low band gap, which could be applied to tandem solar cells. However, most of the work is based on inverted PSCs using PEDOT:PSS as the hole-transport layer as normal-structure PSCs show lower efficiency. In this work, the reason behind the low efficiency of normal-structure SnPb PSCs is elucidated and surface passivation has been tested as a method to overcome the problem. In the case of normal PSCs, at the interface between the titania layer and SnPb perovskite, there are many carrier traps observed originating from Ti-O-Sn bonds. In order to avoid the direct contact between titania and the SnPb perovskite layer, the titania surface is passivated with carboxylic acid C resulting in an efficiency increase from 5.14 to 7.91%. This will provide a direction of enhancing the efficiency of the normal-structure SnPb PSCs through heterojunction engineering.
近年来，锡铅（SnPb）钙钛矿太阳能电池（PSC）的研究备受关注，因为其带隙较低，可应用于串联太阳能电池。然而，大多数研究工作基于使用PEDOT:PSS作为空穴传输层的倒置PSC，因为常规结构的PSC效率较低。在这项工作中，阐明了常规结构SnPb PSC效率低的原因，并测试了表面钝化作为克服该问题的一种方法。在常规PSC中，在二氧化钛层与SnPb钙钛矿之间的界面处，观察到许多源于Ti-O-Sn键的载流子陷阱。为了避免二氧化钛与SnPb钙钛矿层直接接触，用羧酸C对二氧化钛表面进行钝化，效率从5.14%提高到7.91%。这将为通过异质结工程提高常规结构SnPb PSC的效率提供一个方向。
