Tin perovskite solar cells with >1,300 h of operational stability in N2 through a synergistic chemical engineering approach

Jesús Sanchez-Diaz; Rafael S Sánchez; Sofia Masi; Marie Kreĉmarová; Agustín O Alvarez; Eva M Barea; Jesús Rodriguez-Romero; Vladimir S Chirvony; Juan F Sánchez-Royo; Juan P Martinez-Pastor; Iván Mora-Seró

doi:10.1016/j.joule.2022.02.014

Tin perovskite solar cells with >1,300 h of operational stability in N₂ through a synergistic chemical engineering approach

Joule. 2022 Apr 20;6(4):861-883. doi: 10.1016/j.joule.2022.02.014.

Affiliations

¹ Institute of Advanced Materials (INAM), Universitat Jaume I, Av. Sos Baynat, s/n, 12071 Castelló, Spain.
² UMDO, Instituto de Ciencia de los Materiales, Universidad de Valencia, c/ Catedrático J. Beltrán, 2, 46980 Paterna, Spain.
³ Facultad de Química, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México 04510, México.
⁴ MATINÉE: CSIC Associated Unit (ICMM-ICMUV of the University of Valencia), Universidad de Valencia, Valencia, Spain.

Abstract

Despite the promising properties of tin-based halide perovskites, one clear limitation is the fast Sn⁺² oxidation. Consequently, the preparation of long-lasting devices remains challenging. Here, we report a chemical engineering approach, based on adding Dipropylammonium iodide (DipI) together with a well-known reducing agent, sodium borohydride (NaBH₄), aimed at preventing the premature degradation of Sn-HPs. This strategy allows for obtaining efficiencies (PCE) above 10% with enhanced stability. The initial PCE remained unchanged upon 5 h in air (60% RH) at maximum-power-point (MPP). Remarkably, 96% of the initial PCE was kept after 1,300 h at MPP in N₂. To the best of our knowledge, these are the highest reported values for Sn-based solar cells. Our findings demonstrate a beneficial synergistic effect when additives are incorporated, highlight the important role of iodide in the performance upon light soaking, and, ultimately, unveil the relevance of controlling the halide chemistry for future improvement of Sn-based perovskite devices.

Keywords: lead-free semiconductors; ligand-to-metal charge transfer; light-soaking treatment; long-term device stability; metal halide perovskites; photo-redox reactivity of tin and iodine; photoinduced trap-healing effect; photovoltaics; tin perovskite solar cells.