Proceedings of Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP23)
DOI: https://doi.org/10.29363/nanoge.iperop.2023.054
Publication date: 21st November 2022
Perovskite solar cells (PSCs) with state-of-the-art efficiencies consist of thermally unstable methylammonium (MA). Though the MA-free perovskite has superior thermal stability, there is a challenge to control the formation of the δ-perovskite phase which decreases device performance. This work reports on the surface passivation method with multifunctional fluoroarene molecule which suppresses the formation of PbI2 and δ-perovskite phase in MA/Br-free perovskite film. [1] We found that the fluoroarene passivation has significantly impacted the morphology, interface chemistry, and optoelectronic properties of HaP films. The fluoroarene hydrazine passivation effectively mitigates the defects at surface or grain boundaries in perovskite film with fluoroarene-embedded interfacial layer due to stronger halogen bonding with fluoroarene moieties. Therefore, the PSC achieved superior operational stability and a power conversion efficiency (PCE) exceeding 22 % with a large area of ~1 cm2 which is a record-level PCE for MA/Br-free inverted PSCs. [1] This approach is also equally effective in improving the PCE of both narrow and wide bandgap perovskite systems by lowering the open-circuit voltage deficit. [1-4] This report will shed light on the synergetic effect of fluoroarene molecular passivation in film growth and photo-physics of PSCs. [2,5]
This work was also partly supported by JST-Mirai Program Grant Number JPMJMI21E6, Japan.