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

• Published in: Advanced energy and sustainability research Vol. 5; no. 9
• Main Authors: Bojtor, András, Krisztián, Dávid, Korsós, Ferenc, Kollarics, Sándor, Paráda, Gábor, Pinel, Thomas, Kollár, Márton, Horváth, Endre, Mettan, Xavier, Shiozawa, Hidetsugu, Márkus, Bence G., Forró, László, Simon, Ferenc
• Format: Journal Article
• Language: English
• Published: Wiley-VCH 01-09-2024
• Subjects: charge‐carrier lifetime; perovskites; photoconductivity; photonic applications
• ISSN: 2699-9412; 2699-9412
• DOI: 10.1002/aesr.202400043

Understanding the recombination lifetime of charge carriers (τc$\left(\tau\right)_{\text{c}}$) 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 τc$\left(\tau\right)_{\text{c}}$ approaching 100 μs at room temperature. Utilizing time‐resolved microwave‐detected photoconductivity decay in conjunction with injection dependence, it is found that τc$\left(\tau\right)_{\text{c}}$ 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.
Temperature‐ and power‐dependent time‐resolved microwave photoconductivity decay (TRMCD) measurements are presented on CsPbBr3 crystals for 20–300 K. Charge‐carrier lifetime is 1 ms below 200 K and 100 μs at 300 K. The injection dependent TRMCD measurements indicate the observed ultralong effect to be caused by charge‐carrier trapping in shallow traps.