EU PVSEC Programme Online
EU PVSEC 2020, 7 - 11 September 2020
Presentation: 3BV.1.29 Synthesis of Perovskite Films for Photovoltaics: Influence of the Reagents’ Ratio on the Material Properties
Type: Visual
Date: Tuesday, 8th September 2020
08:30 - 10:00
Author(s): V.P. Kostylyov, A.V. Sachenko, I.O. Sokolovskyi, V.M. Vlasiuk, P.V. Torchyniuk, O.I. V'yunov, A.G. Belous, A.I. Shkrebtii / Chkrebtii
Presenter / Speaker: I.O. Sokolovskyi, NAS ISP, Kiev, Ukraine, A.I. Shkrebtii / Chkrebtii, Ontario Tech University, Oshawa, Canada
Event: Conference Conference
Session: 3BV.1 Perovskites
Type(s) of Access:  Conference Registration
Topic: 3. 1 Perovskites
Keywords: Spectroscopy, Surface Photovoltage, Optical Properties, Perovskite
Summary / Abstract: We have studied, promising for photovoltaic applications, properties of perovskite CH3NH3PbI2.98Cl0.02 films, depending on the ratio of the precursors PbI2 and CH3NH3I during their synthesis. The 1:1, 1:2, and 1:3 ratios of PbI2 and CH3NH3I has been used. Peculiarities of the film morphology and determination of unit cell parameters are discussed. We report 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 are determined. We have found that the materials’ band gap depends on the ratio of the precursors and equals to 1.59 eV, 1.62 eV 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. We established that the spectral dependencies 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.