Thickness-Dependence of Exciton-Exciton Annihilation in Halide Perovskite Nanoplatelets

Autor: Gramlich, Moritz, Bohn, Bernhard J., Tong, Yu, Polavarapu, Lakshminarayana, Feldmann, Jochen, Urban, Alexander S.
Rok vydání: 2020
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1021/acs.jpclett.0c01291
Popis: Exciton-exciton annihilation (EEA) and Auger recombination are detrimental processes occurring in semiconductor optoelectronic devices at high carrier densities. Despite constituting one of the main obstacles for realizing lasing in semiconductor nanocrystals (NCs), the dependencies on NC size are not fully understood, especially for those with both weakly and strongly confined dimensions. Here, we use differential transmission spectroscopy to investigate the dependence of EEA on the physical dimensions of thickness-controlled 2D halide perovskite nanoplatelets (NPls). We find the EEA lifetimes to be extremely short on the order of 7-60 ps. Moreover, they are strongly determined by the NPl thickness with a power-law dependence according to {\tau}_2~d^5.3. Additional measurements show that the EEA lifetimes also increase for NPls with larger lateral dimensions. These results show that a precise control of the physical dimensions is critical for deciphering the fundamental laws governing the process especially in 1D and 2D NCs.
Databáze: arXiv