Role of Polar Phonons in the Photo Excited State of Metal Halide Perovskites.

ABSTRACT: The development of high efficiency perovskite solar cells has sparked a multitude of measurements on the optical properties of these materials. For the most studied methylammonium(MA)PbI3 perovskite, a large range (6-55 meV) of exciton binding energies has been reported by various experiments. The existence of excitons at room temperature is unclear. For the MAPbX3 perovskites we report on relativistic Bethe-Salpeter Equation calculations (GW-BSE). This method is capable to directly calculate excitonic properties from first-principles. At low temperatures it predicts exciton binding energies in agreement with the reported 'large' values. For MAPbI3, phonon modes present in this frequency range have a negligible contribution to the ionic screening. By calculating the polarization in time fr

SUBMITTER: Bokdam M 

PROVIDER: S-EPMC4923852 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature