ABSTRACT We present a simplistic approach to determine the electronic-bandgap (Eg) and exciton binding energy (Ex) of hybrid perovskite (CH3NH3PbX3 where X = Cl, Br or I) semiconductor film. In this study, we show the role of halide... more
ABSTRACT We present a simplistic approach to determine the electronic-bandgap (Eg) and exciton binding energy (Ex) of hybrid perovskite (CH3NH3PbX3 where X = Cl, Br or I) semiconductor film. In this study, we show the role of halide cation (X-) on Eg and Ex by a simple room temperature UV-Vis absorption spectrum measurements and model our results using Elliot’s theory of Wannier exciton model to determine the Eg and Ex. We also found that the disorder primarily arises from structural and not composition disorder, this is just a consequence of the fact the Urbach tail, which is a measure of disorder is reasonably independent of the halide cation among three perovskite films.
