Efficient post-treatment strategy for enhancing the performance and stability of the inverted perovskite solar cells based on Boc-D-Val-OH

Abstract

Recombination losses from perovskite/fullerene interface issues significantly limit the performance and stability of inverted perovskite solar cells (PSCs). A simple post-treatment method based on Boc-D-Val-OH (BDVO) is developed to overcome these issues. A systematic study has been conducted on the impact of BDVO on the physical properties of the film and the device. The results confirm that BDVO post-treatment can passivate trap states of the perovskite film surface, improve contact at the perovskite/fullerene interface, and enhance the built-in interface electrical field of the device. That improvements lead to enhanced carrier transport dynamics, as well as improves the performance and stability of PSCs. A relatively higher power conversion efficiency (PCE) of 23.02 % is achieved by BDVO post-treatment. Additionally, after storage in air (30–40 RH%) for 264 h (12 days) and in N₂ for 312 h (13 days), the PCE of the BDVO devices can remain at 90 % and 95 % of their initial values, respectively, while the control devices under the same exposure conditions only maintain 83 % and 88 % of their initial PCE values. The study sheds light on the pathway for perovskite/fullerene interface material selection and design, aimed at enhancing device performance and stability through streamlined post-treatment.