Hot-carrier cooling and photoinduced refractive index changes in organic-inorganic lead halide perovskites.

ABSTRACT: Metal-halide perovskites are at the frontier of optoelectronic research due to solution processability and excellent semiconductor properties. Here we use transient absorption spectroscopy to study hot-carrier distributions in CH3NH3PbI3 and quantify key semiconductor parameters. Above bandgap, non-resonant excitation creates quasi-thermalized carrier distributions within 100 fs. During carrier cooling, a sub-bandgap transient absorption signal arises at ∼ 1.6 eV, which is explained by the interplay of bandgap renormalization and hot-carrier distributions. At higher excitation densities, a 'phonon bottleneck' substantially slows carrier cooling. This effect indicates a low contribution from inelastic carrier-impurity or phonon-impurity scattering in these polycrystalline materials, which s

SUBMITTER: Price MB 

PROVIDER: S-EPMC4598728 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature