An efficient and stable tin-based perovskite solar cell passivated by aminoguanidine hydrochloride

It is challenging to fabricate a simultaneously high-performance and stable Sn-based perovskite device owing to the inferiority of the Sn-based perovskite film and the rapid oxidation of Sn 2+ . Herein, a simple approach was employed and involved introducing an additive of aminoguanidine hydrochloride (NH 2 GACl) into a perovskite precursor solution to prepare efficient Sn-based perovskite solar cells. A higher film quality was obtained, due to the formation of strong hydrogen bonding between halide ions in the perovskite and NH 2 GACl, which helped to passivate the defects and lessen the rate of Sn 2+ oxidation. Also, the addition of NH 2 GACl was indicated to effectively adjust the energy level alignment between Sn-based perovskite and the adjacent layer, with this adjustment facilitating the charge transport. The perovskite device modified with NH 2 GACl achieved a power conversion efficiency of up to 7.3%, and retained 90% of its initial efficiency after 30 days in a nitrogen glovebox without being encapsulated. Aminoguanidine hydrochloride passivated Sn-perovskite with a power conversion efficiency of 7.3%.