Excitation Density Effects in the Luminescence Yield and Kinetics of MAPbBr[sub.3] Single Crystals

The luminescent Z-scan technique with time resolution is applied to the study of the luminescence properties of CH[sub.3] NH[sub.3] PbBr[sub.3] single crystals representative of the family of hybrid organic–inorganic lead perovskites successfully applied recently in photovoltaics and currently investigated as potential nanosecond scintillators. The third harmonic of Ti-sapphire laser (λ = 266 nm) with a pulse duration of 26 fs and 1 kHz frequency was applied for the luminescence excitation creating the charge carriers with the estimated density from 10[sup.17] to 10[sup.21] cm[sup.−3] in the temperature range from 13 to 300 K. Temperature and excitation density dependence of the luminescence yield and kinetics is interpreted with the consideration of the temperature-dependent binding of electrons and holes into excitons, a saturation of defects responsible for the non-radiative relaxation channel competing with exciton creation; absorption saturation resulting in the increased penetration depth of the excitation radiation and hence the increased contribution of the re-absorption.