Auger recombination and intraband absorption of two-photon-excited carriers in colloidal CdSe quantum dots

Abstract

Auger recombination, quantized Auger rate, and intraband absorption of two-photon-excited carriers in colloidal CdSe quantum dots have been investigated systematically with femtosecond Z scans and transient absorption measurements. The Auger constant is revealed to be on the order of 10 -30 cm6 s-1, while the intraband absorption cross sections are found to be in the range of 10-18-10-17 cm 2. The authors' experimental evidence demonstrates that the Auger recombination or the intraband absorption takes place under the condition that the average electron-hole pair per quantum dot is in excess of the unity. © 2007 American Institute of Physics.