Optoelectronic and stability properties of quasi-2D alkylammonium based perovskites

• DOI: 10.48550/arxiv.2210.04596
• Publication Date: 2022-01-01
• Authors: N. Filipoiu; Anca G. Mirea; Sarah Derbali; C. -A. Pantis-Simut; D. -V. Anghel; Andrei Manolescu; Ioana Pintilie; Mihaela Florea; George Alexandru ...
• Keywords: Formamidinium; Thermogravimetric analysis

Electronic and stability properties of quasi-2D alkylammonium perovskites are investigated using density functional theory (DFT) calculations validated experimentally on selected classes compounds. Our analysis is focused perovskite structures formula (A)$_2$(A$'$)$_{n-1}$Pb$_n$X$_{3n+1}$, with large cations A = butyl-, pentyl-, hexylammonium (BA, PA, HXA), small A$'$ methylammonium, formamidinium, ethylammonium, guanidinium (MA,FA,EA,GA) halogens X I, Br, Cl. The role the halogen ions outlined for band structure, defect formation energies. Two opposing trends found absorption efficiency versus stability, latter being assessed respect to possible degradation mechanisms. Experimental validation performed based pentylammonium cations, namely: (PA)$_2$PbX$_4$ (PA)$_2$(MA)Pb$_2$X$_7$, synthesized by antisolvent-assisted vapor crystallization. Structural optical inline DFT calculations. In addition, thermogravimetric shows an enhanced bromide chloride compounds, in agreement theoretical predictions.