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

• Published in: Physical chemistry chemical physics : PCCP 2023-01, Vol.25 (4), p.3323-3331
• Main Authors: Filipoiu, N, Mirea, Anca G, Derbali, Sarah, Pantis-Simut, C.-A, Anghel, D.-V, Manolescu, A, Pintilie, Ioana, Florea, Mihaela, Nemnes, G. A
• Format: Article
• Language: English
• Subjects: Cations; Crystal defects; Crystallization; Density functional theory; Free energy; Halogens; Heat of formation; Mathematical analysis; Optoelectronics; Perovskites; Stability analysis; Thermogravimetric analysis
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp04748a

Electronic and stability properties of quasi-2D alkylammonium perovskites are investigated using density functional theory (DFT) calculations and validated experimentally on selected classes of compounds. Our analysis is focused on perovskite structures of formula (A) 2 (A′) n −1 Pb n X 3 n +1 , with large cations A = butyl-, pentyl-, hexylammonium (BA, PA, HXA), small cations A′ = methylammonium, formamidinium, ethylammonium, guanidinium (MA, FA, EA, GA) and halogens X = I, Br, Cl. The role of the halogen ions is outlined for the band structure, stability and defect formation energies. Two opposing trends are found for the absorption efficiency versus stability, the latter being assessed with respect to possible degradation mechanisms. Experimental validation is performed on quasi-2D perovskites based on pentylammonium cations, namely: (PA) 2 PbX 4 and (PA) 2 (MA)Pb 2 X 7 , synthesized by antisolvent-assisted vapor crystallization. Structural and optical analysis are inline with the DFT based calculations. In addition, the thermogravimetric analysis shows an enhanced stability of bromide and chloride based compounds, in agreement with the theoretical predictions. Electronic and stability properties of quasi-2D alkylammonium perovskites are investigated using density functional theory (DFT) calculations and validated experimentally on selected classes of compounds.