Formamidinium lead iodide perovskite thin films formed by two-step sequential method: solvent-morphology relationship

0567642 - ÚMCH 2024 RIV CH eng J - Journal Article
Cimrová, Věra - Guesmi, Mariem - Eom, S. - Kang, Y. - Výprachtický, Drahomír
Formamidinium lead iodide perovskite thin films formed by two-step sequential method: solvent-morphology relationship.
Materials. Roč. 16, č. 3 (2023), č. článku 1049. E-ISSN 1996-1944
R&D Projects: GA ČR(CZ) GC20-15498J
Institutional support: RVO:61389013
Keywords : perovskite * formamidinium lead iodide * morphology
OECD category: Polymer science
Impact factor: 3.4, year: 2022
Method of publishing: Open access
https://www.mdpi.com/1996-1944/16/3/1049

Thin films made of formamidinium lead iodide (FAPbI3) perovskites prepared by a two-step sequential deposition method using various solvents for formamidinium iodide (FAI) - isopropanol, n-butanol and tert-butanol, were studied with the aim of finding a correlation between morphology and solvent properties to improve film quality. They were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and their photophysical properties were studied by means of absorption and photoluminescence (PL) spectroscopies. XRD patterns, absorption and PL spectra proved α-phase formation for all selected solvents. An excessive amount of PbI2 found in perovskite films prepared with n-butanol indicates incomplete conversion. Thin film morphology, such as grain and crystallite size, depended on the solvent. Using tert-butanol, thin films with a very large grain size of up to several micrometers and with preferred crystallite orientation were fabricated. The grain size increased as follows: 0.2–0.5, 0.2–1 and 2–5 µm for isopropanol, n-butanol and tert-butanol, respectively. A correlation between the grain size and viscosity, electric permittivity and polarizability of the solvent could be considered. Our results, including fabrication of perovskite films with large grains and fewer grain boundaries, are important and of interest for many optoelectronic applications.

Permanent Link: https://hdl.handle.net/11104/0340484