Abstract
We perform a theoretical and experimental study of the optical properties of a perovskite prepared by a vapor-assisted solution process, motivated in part by very high photovoltaic cell efficiencies. Several widespread theoretical approaches are used in an attempt to determine the most appropriate approach which would reproduce the experimental electronic structure and optical properties of the perovskite. We compare a semilocal approximation to the density functional theory with hybrid functionals and time-dependent hybrid functional calculations, evaluating the effects of exchange tuning and spin-orbit coupling. Using these methods we calculate the electronic structure, optical absorption spectrum, and frequency-dependent dielectric function of the perovskite. The results are compared to the experimentally obtained dielectric functions acquired from ellipsometry measurements. We demonstrate that inclusion of spin-orbit coupling in theoretical calculations is critical in describing the electronic and optical properties of the perovskite. Good agreement with experimental data is achieved when the optical spectra are computed using time-dependent hybrid density functional theory with spin-orbit coupling.
2 More- Received 17 May 2016
- Revised 22 July 2016
DOI:https://doi.org/10.1103/PhysRevB.94.075206
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