Suppressed Ion Migration in Reduced-Dimensional Perovskites Improves Operating Stability

By Ziru Huang, Andrew H. Proppe, H. Tan, M. Saidaminov, F. Tan, Anyi Mei, Chih-Shan Tan, Mingyang Wei, Yi Hou, Hongwei Han and 2 more. ACS Energy Letters, 2019

154 citations recorded by the source corpus.

Impressive progress in halide perovskite solar cells motivates further work to improve operating stability. It is known that ion-migration-driven decomposition represents a degradation pathway in perovskite solar cells and that it can occur within the perovskite material even in well-encapsulated devices. Here we find that quasi-two-dimensional (2.5D) perovskites suppress this ion-migration-induced degradation. Using TOF-SIMS, we confirm that iodide migration occurs in bulk perovskite photovoltaic devices operating at their maximum power point (MPP). We observe that iodine ions migrate across the spiro-OMeTAD layer to the spiro/gold contact interface, oxidizing and deteriorating the gold at the interface. In contrast, we find that large ⟨n⟩ 2.5D perovskites exhibit a significantly reduced rate of ion migration compared to 3D devices and exhibit less than 1% relative PCE loss in over 80 h of continuous operation at MPP, whereas the PCE of 3D devices diminishes by more than 50% within the first 24 h.

Subfields: Electrical and Electronic Engineering, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/c5cb1ce30a006234313e4b18e5d91fb9ca28aa9a