Open AccessInfluence of the reagents’ ratio on photoelectric and optical properties of perovskite films for photovoltaics
Author(s) -
V. P. Kostylyov,
А. В. Саченко,
I.O. Sokolovskyi,
V.M. Vlasiuk,
Pavlo Torchyniuk,
O. I. V’yunov,
А. Г. Белоус,
A. Shkrebtii,
prospect Palladina
Publication year - 2021
Publication title -
semiconductor physics, quantum electronics and optoelectronics/semiconductor physics quantum electronics and optoelectronics
Language(s) - English
Resource type - Journals
eISSN - 1605-6582
pISSN - 1560-8034
DOI - 10.15407/spqeo24.03.295
Subject(s) - band gap , photoelectric effect , materials science , perovskite (structure) , microstructure , absorption (acoustics) , thin film , analytical chemistry (journal) , absorption edge , surface photovoltage , chemistry , optoelectronics , nanotechnology , crystallography , organic chemistry , physics , quantum mechanics , spectroscopy , metallurgy , composite material
The properties of the synthesized films of organic-inorganic perovskites CH3NH3PbI3 obtained at various ratios of starting reagents (PbI2 and CH3NH3I) have been studied. As a solvent, we used chemically pure dried dimethylformamide (DMF). Organic-inorganic perovskites are promising for photovoltaic applications. It has been shown that regardless of the ratio of the starting reagents, single-phase perovskites are formed, at the same time the microstructure of the films changes significantly. It has been reported photoelectric and optical properties of synthesized films, namely: experimental and theoretical spectral dependences of the low-signal surface photovoltage and transmission. The band gap and the Urbach parameter dependence on the ratio of precursors were determined. It has been found that the materials’ band gap depends on the ratio of precursors and equals to 1.59, 1.62 and 1.57 eV, while the characteristic Urbach energy equals to 18, 19 and 22 meV for the PbI2:CH3NH3I films with PbI2 ratio of 1:1, 1:2 and 1:3, respectively. It has been ascertained that the spectral dependences of the low-signal surface photovoltage are much more sensitive to the material microstructure and its electronic structure close to the absorption edge, while the optical transmission spectra are not so sensitive. The limiting value of the short-circuit current density for the films with different PbI2 and CH3NH3I ratios has been determined.