Stable NiOx-based inverted perovskite solar cells achieved by passivation of multifunctional star polymer

• Published in: Nano energy Vol. 112; p. 108506
• Main Authors: Pu, Xingyu, Zhao, Junsong, Li, Yongjiang, Zhang, Yixin, Loi, Hok-Leung, Wang, Tong, Chen, Hui, He, Xilai, Yang, Jiabao, Ma, Xiaoyan, Li, Xuanhua, Cao, Qi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2023
• Subjects: Inverted perovskite solar cells; Multifunctional passivation; Operational stability; Star polymer; Multifunctional passivation; Star polymer; Inverted perovskite solar cells; Operational stability
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2023.108506

Perovskite materials have excellent photoelectric properties and are a hot spot in international research. However, there are deep/shallow energy level traps in the grain boundaries (GBs)/surface of perovskite thin films, which affect the optoelectronic performance of perovskite solar cells (PSCs). Here, we design and synthesize a three-dimensional star-shaped polymer with various groups to regulate the light-absorbing layer of perovskite. The eight branched chains of multifunctional star polymer are rich in CO, N = N, N = O, and –CF3 functional groups, which are used to passivate uncoordinated lead ions and to immobilize methylamine, formamidine cations on the GBs/surface of perovskite films. Simultaneous passivation of deep-level defects and suppression the appearance of shallow-level defects on the perovskite surface/GBs, thereby greatly improving the optoelectronic performance of PSCs. Compared with the efficiency of 22.38 % of the reference device, the efficiency of the multifunctional star polymer incorporated inverted device reaches 24.03 %. Moreover, the multifunctional star-shaped polymer modified inverted-encapsulation device also exhibits excellent operational stability, maintaining 80 % of the initial efficiency for more than 5500 h. [Display omitted] •PTHM polymer suppresses both deep and shallow-level defects on perovskite surface/grain boundaries.•The multifunctional star-shaped polymer modified inverted PSC obtains the best PCE of 24.03 % and FF of 0.856.•The encapsulated PTHM-modified device exhibits significantly advancement of operational stability.•The T80 of operational stability lasts almost 5516 h.