Open AccessDetermination of complex optical constants and photovoltaic device design of all-inorganic CsPbBr3 perovskite thin films
Author(s) -
Wensheng Yan,
Lingyun Mao,
Peiyang Zhao,
Adrian Mertens,
Stephan Dottermusch,
Hang Hu,
Zhong Jin,
Bryce S. Richards
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.392246
Subject(s) - materials science , perovskite (structure) , optics , thin film , ellipsometry , optoelectronics , refractive index , photoactive layer , solar cell , nanotechnology , polymer solar cell , chemistry , physics , crystallography
All-inorganic perovskites exhibit interesting properties and unprecedented stability compared to organic-inorganic hybrid lead halide perovskites. This work focuses on depositing and characterizing cesium lead bromide (CsPbBr 3 ) thin films and determining their complex optical constants, which is a key requirement for photovoltaic device design. CsPbBr 3 thin films are synthesized via the solution method followed by a hot-embossing step to reduce surface roughness. Variable angle spectroscopic ellipsometry measurements are then conducted at three angles (45°, 55°, and 65°) to obtain the ellipsometric parameters psi (Ψ) and delta (Δ). For the present model, bulk planar CsPbBr 3 layer is described by a one-dimensional graded index model combined with the mixture of one Tauc-Lorentz oscillator and two Gaussian oscillators, while an effective medium approximation with 50% air void is adopted to describe surface roughness layer. The experimental complex optical constants are finally determined in the wavelength range of 300 to 1100 nm. Furthermore, as a design example demonstration, the simulations of single-junction CsPbBr 3 solar cells are conducted via the finite-difference time-domain method to investigate the properties of light absorption and photocurrent density.