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

Understanding the recombination lifetime of charge carriers (${\tau }_c$) 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 ${\tau }_c$ approaching 100 μs at room temperature. Utilizing time-resolved microwave-detected photoconductivity decay in conjunction with injection dependence, it is found that ${\tau }_c$ 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.