Laplace current deep level transient spectroscopy measurements of defect states in methylammonium lead bromide single crystals

Abstract

We present a measurement of the energies and capture cross-sections of defect states in methylammonium lead bromide (MAPbBr3) single crystals. Using Laplace current deep level transient spectroscopy (I-DLTS), two prominent defects were observed with energies 0.17 eV and 0.20 eV from the band edges, and further I-DLTS measurements confirmed that these two defects are bulk defects. These results show qualitative agreement with theoretical predictions, whereby all of the observed defects behave as traps rather than as generation-recombination centers. These results provide one explanation for the high efficiencies and open-circuit voltages obtained from devices made with lead halide perovskites.