Hot excitons cooling and multiexcitons Auger recombination in PbS quantum dots
- 8 February 2021
- journal article
- research article
- Published by IOP Publishing in Nanotechnology
- Vol. 32 (18), 185701
- https://doi.org/10.1088/1361-6528/abdf03
Abstract
In the past few years, lead chalcogenide quantum dots (QDs) have attracted attention as a new system with a strong quantum confinement effect. In this paper, the hot-excitons cooling and Auger recombination of multiexcitons in PbS QDs are investigated by the femtosecond time-resolved transient absorption spectroscopy. The results show that the excitons dynamics in PbS QDs are closely related to the pump-photon energy and pump-pulse energy. Multiexcitons generate when the excess energy of the absorbed photons is larger than the bandgap energy in PbS QDs. The hot-excitons cooling lifetime increases but the Auger recombination lifetime decreases as the pump-photon energy and the pump-pulse energy increase. Besides, there is a competitive relation between multiple-excitons generation and hot-excitons cooling. The dynamics results of the formation and relaxation of multiexcitons in PbS QDs would shed light on the further understanding of the interaction between excitons and photons in the optoelectronic application based on PbS QDs.Keywords
Funding Information
- National Natural Science Foundation of China (11804084)
- Education Department of Henan Province (19A140011)
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