A detailed understanding of the carrier dynamics and emission characteristics
of organic-inorganic lead halide perovskites is critical for their
optoelectronic and energy harvesting applications. In this work, we reveal the
impact of the crystal lattice disorder on the photo-generated electron-hole
pairs through low-temperature photoluminescence measurements. We provide strong
evidence that the intrinsic disorder forms a sub-bandgap tail density of
states, which determines the emission properties at low temperature. The PL
spectra indicate that the disorder evolves with increasing temperature,
changing its character from static to dynamic. This change is accompanied by a
rapid drop of the PL efficiency, originating from the increased mobility of
excitons/polarons, which enables them to reach deep non-radiative recombination
centers more easily