The electronic stability of tin-halide perovskite charged regions. Issue 5 (10th February 2022)

• Record Type: Journal Article
• Authors: Underwood, Cameron; Wang, Zhou; Shao, Guosheng; Carey, J. David; Silva, S. Ravi P.
• Is Part Of: Materials advances. Volume 3:Issue 5(2022)
• Page Start: 2524
• Page End: 2532
• Publication Date: 2022-02-10
• Subjects: 620.11
• DOI: 10.1039/d1ma01232k
• Languages: English
• ISSNs: 2633-5409

Abstract

Abstract : Evolution of the electronic structure and partial oxidation state of tin and iodine in ASnI3, where A = CH3 NH3 (MA), CH(NH2 )2 (FA) and Cs, is reported with a view to develop stable, long-term, non-toxic halide-perovskite solar cells. Abstract : We report on the evolution of the electronic structure and partial oxidation state of tin and iodine in ASnI3, where A = CH3 NH3 (MA), CH(NH2 )2 (FA) and Cs, with an aim to develop stable, long-term, non-toxic halide-perovskite solar cells. Although charge cannot be directly removed from specific elements, we show a reduction in the charge of primarily SnI3 in a hypothetical [ASnI3 ] 2+ unit cell, which was calculated due to the valence band edge being dominated by Sn 5s and I 5p anti-bonding states, accompanied by a reduction in the unit cell volume of [ASnI3 ] 2+ compared to ASnI3 . The band structure calculations show semiconducting behaviour in ASnI3 with metallic behaviour in [ASnI3 ] 2+, and similar behaviour is also found for APbI3 and [APbI3 ] 2+, where the Pb atoms exhibit partial charge compared to Sn. This study allows for the analysis of localised charged regions, directing the contribution of the electronic states to stability in perovskite solar absorbers, such as interface recombination and deep trap states.