Dimethylammonium Incorporation in Lead Acetate Based MAPbI3 Perovskite Solar Cells. Issue 22 (9th October 2018)

• Record Type: Journal Article
• Authors: Franssen, Wouter M. J.; Bruijnaers, Bardo J.; Portengen, Victor H. L.; Kentgens, Arno P. M.
• Is Part Of: Chemphyschem. Volume 19:Issue 22(2018)
• Page Start: 3107
• Page End: 3115
• Publication Date: 2018-10-09
• Subjects: Dimethylammonium -- Hybrid perovskite -- Methylammonium lead iodide -- NMR -- Photovoltaics; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201800732
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Over the last years, several different pathways have been suggested for producing perovskite thin films for solar cell applications. While the merit of these methods with respect to the solar cell efficiency have been shown, the actual composition of the resulting thin films is often not investigated. Here, we show that methylammonium lead iodide films produced using lead acetate as a lead source can have up to 15 % dimethylammonium incorporated into their crystal structure, even though this ion is often consider to be too large for incorporation. The origin of this ion lies in the precursor solution, where it is formed in a reaction that is facilitated by the basic character of the acetate ions. We further show that these dimethylammonium ions are incorporated in a random fashion throughout the crystal structure, owing to the lack of observable ordered domains. Abstract : Serendiptic mixing of organic cations in perovskites : The 13 C NMR spectrum reveals an unexpected resonance for perovskite thin films synthesised using lead acetate as a precursor. This extra line appears to be due to the dimethylammonium cation, which is formed in considerable amount in the perovskite precursor solution due a base catalysed degradation of the solvent (DMF). This ion is subsequently incorporated into the perovskite lattice in a random fashion.