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Two-photon excited biexciton photoluminescence in colloidal nanoplatelets CdSe/CdS
The photoluminescence features under resonant two-photon excitation of a light-hole – electron exciton transition in CdSe/CdS nanoplatelets colloidal solution (536 nm, 1lh-1e) were investigated. The discovered power-law dependence of their photoluminescence intensity on the excitation laser femtosecond pulses intensity was revealed to be relating to biexciton radiation. In addition, the conditions for the photoluminescence growth and quenching were determined depending on the concentration and pump intensity. We believe the results presented in our study will provide a clearer comprehension of the electro-optical processes physics in CdSe/CdS nanoplatelets, which will expand the scope of their application, including frequency up-conversion amplification and lasing, also be beneficial for biosensor design.