Title :
Ultrafast intraband relaxation in colloidal quantum dots
Author :
Hendry, E. ; Pijpers, J. ; Bonn, M.
Author_Institution :
Sch. of Phys., Univ. of Exeter, Exeter
Abstract :
We independently determine the subpicosecond cooling rates for holes and electrons in CdSe quantum dots using time-resolved luminescence and time-resolved terahertz spectroscopy. The rate of hole cooling, following photoexcitation of the quantum dots, depends critically on the electron excess energy. This constitutes a direct proof of electron-to-hole energy transfer, the hypothesis behind the Auger cooling mechanism proposed in quantum dots, which is found to occur on a 1 plusmn 0.15 ps time scale.
Keywords :
Auger effect; II-VI semiconductors; cadmium compounds; high-speed optical techniques; photoexcitation; photoluminescence; semiconductor quantum dots; time resolved spectra; wide band gap semiconductors; Auger cooling; CdSe; colloidal quantum dots; electron excess energy; electron-to-hole energy transfer; hole cooling; photoexcitation; subpicosecond cooling rates; time-resolved luminescence; time-resolved terahertz spectroscopy; ultrafast intraband relaxation; Charge carrier processes; Cooling; Electromagnetic wave absorption; Electron optics; Energy exchange; Excitons; Phonons; Physics; Quantum dots; Ultrafast optics;
Conference_Titel :
Infrared, Millimeter and Terahertz Waves, 2008. IRMMW-THz 2008. 33rd International Conference on
Conference_Location :
Pasadena, CA
Print_ISBN :
978-1-4244-2119-0
Electronic_ISBN :
978-1-4244-2120-6
DOI :
10.1109/ICIMW.2008.4665612
