Different emissive states in the bulk and at the surface of methylammonium lead bromide perovskite revealed by two-photon micro-spectroscopy and lifetime measurements
Two photon photoluminescence (2PPL) from single crystals of methyl ammonium lead bromide (CH3NH3PbBr3, MAPbBr3) is studied. We observe two components in the 2PPL spectra, which we assign to the photoluminescence (PL) from the carrier recombination at the band edge and the recombination due to self-trapping of excitons. The PL Stokes shift of self-trapped excitons is about 100 meV from the band-ga
