Enhancement of Photocarrier Lifetimes in Infrared-Laser-Deposited CsPbBr3 Films Using a CsBr Underlayer Enhancement of Photocarrier Lifetimes in Infrared-Laser-Deposited CsPbBr3 Films Using a CsBr Underlayer AITranslate

Basic Information:

DOI：https://doi.org/10.1021/acsaelm.3c00672

Chinese Library Classification Number:

Citation Information:

This study used photocarrier lifetime measurements to demonstrate that the insertion of a CsBr underlayer enhances the quality of CsPbBr3 films grown via infrared (IR) laser deposition. Thermal desorption spectrometry indicated that the CsPbBr3 crystal tended to be Cs-deficient under vacuum. In fact, direct growth of a CsPbBr3 film on an α-Al2O3(0001) substrate resulted in contamination by an impurity phase of CsPb2Br5, thereby degrading the optical characteristics of the CsPbBr3 films. To mitigate CsPb2Br5 contamination, a two-step film preparation process was employed to obtain the growth window for the IR-laser deposition of the CsPbBr3 thin films. First, a CsBr underlayer was deposited at room temperature. CsPbBr3 thin films were subsequently deposited onto the underlayer at 150 °C. Consequently, the CsBr underlayer was found to suppress the precipitation of the impurity phase and improve the functional properties of the CsPbBr3 films. Furthermore, photocarrier lifetime measurements were performed to assess the quality of the CsPbBr3 thin films. Notably, time-resolved microwave conductivity measurements revealed that the CsBr underlayer not only doubled the photocarrier lifetime but also tripled the photoconductivity. Thus, the use of a thin underlayer is expected to be an essential synthesis parameter for fine-tuning the growth window and improving the physical properties of halide perovskite films.