Bandgap-universal passivation enables stable perovskite solar cells with low photovoltage loss
Yen‐Hung Lin, Vikram Vikram, Fengning Yang, X. K. Cao, Akash Dasgupta, Robert D. J. Oliver, Aleksander M. Ulatowski, M. McCarthy, Xinyi Shen, Qimu Yuan, M. Greyson Christoforo, Fion Sze Yan Yeung, Michael B. Johnston, Nakita K. Noel, Laura M. Herz, M. Saïful Islam, Henry J. Snaith
Abstract
The efficiency and longevity of metal-halide perovskite solar cells are typically dictated by nonradiative defect-mediated charge recombination. In this work, we demonstrate a vapor-based amino-silane passivation that reduces photovoltage deficits to around 100 millivolts (>90% of the thermodynamic limit) in perovskite solar cells of bandgaps between 1.6 and 1.8 electron volts, which is crucial for tandem applications. A primary-, secondary-, or tertiary-amino-silane alone negatively or barely affected perovskite crystallinity and charge transport, but amino-silanes that incorporate primary and secondary amines yield up to a 60-fold increase in photoluminescence quantum yield and preserve long-range conduction. Amino-silane-treated devices retained 95% power conversion efficiency for more than 1500 hours under full-spectrum sunlight at 85°C and open-circuit conditions in ambient air with a relative humidity of 50 to 60%.