UV degradation mechanism of TiO 2 -based perovskite solar cells studied by pump-probe spectroscopy
Journal
Proceedings of SPIE - The International Society for Optical Engineering
Journal Volume
11366
Date Issued
2020
Author(s)
Luo, C.-W.
Thilakan, A.P.
Li, J.-X.
Chen, T.-P.
Li, S.-S.
Yabushita, A.
Osada, M.
Tsukagoshi, K.
Sasaki, T.
Abstract
In this study, the microscopic carrier dynamics that govern the UV stability of perovskite solar cells was investigated using pump-probe spectroscopy. In conventional perovskite solar cells, the UV-active oxygen vacancy in compact TiO2 prohibits current generation after UV degradation. On the other hand, the dominant vacancy type in 2D Ti1-xO2 atomic sheet transporting layer (ASTL) is a titanium vacancy, not UV-sensitive. Consequently, the carrier recombination are suppressed and further extends UV stability in perovskite solar cells with a 2D Ti1-xO2 ASTL. The dynamics of electron diffusion, electron injection, and hot hole transfer processes are found to be less sensitive to the UV irradiation. The ultrafast time-resolved data shown here clearly represent a close correlation between the carrier dynamics and UV aging of perovskite, thus providing insight into the origin of UV-induced degradation in perovskite solar cells.
SDGs
Type
conference paper