Millisecond-Scale Charge-Carrier Recombination Dynamics in the CsPbBr3 Perovskite

Abstract

Understanding the recombination lifetime of charge carriers ((Formula presented.)) is essential for the diverse applications of photovoltaic materials, such as perovskites. The study on the inorganic perovskite, CsPbBr3, reveals recombination dynamics exceeding 1 ms below 200 K and (Formula presented.) approaching 100 μs at room temperature. Utilizing time-resolved microwave-detected photoconductivity decay in conjunction with injection dependence, it is found that (Formula presented.) is dominated by impurity charge trapping. The observed injection dependence is well corroborated by modeling of the trap mechanism. The ultralong decay time is also consistent with photoconductivity measurements with a continuous-wave excitation at powers corresponding to around 1 Sun irradiation. While charge-carrier trapping may, in theory, impose limitations on the photovoltaic efficiency of single-cell devices, it can also contribute to increased efficiency in tandem cells and find applications in photodetection, photocatalysis, and quantum information storage.