Title :
Radiative lifetimes of negatively charged excitons in CdTe quantum wells
Author :
Ciulin, V. ; Kossacki, P. ; Kutrowski, M. ; Esser, A. ; Haacke, S. ; Ganiere, J.-D. ; Wojtowicz, T. ; Deveaud, B.
Author_Institution :
Dept. of Phys., Swiss Fed. Inst. of Technol., Lausanne, Switzerland
Abstract :
Summary form only given. Using picosecond photoluminescence (PL), we have investigated the temperature dependence of the radiative lifetime of the negatively charged exciton (X/sup -/) in CdTe quantum wells (QWs). The X/sup $/lifetime is found to increase from 70 ps at 2 K up to about 200 ps at 30 K. The increase is linear for temperatures bigger than 5 K and reveals that X/sup $/cannot be treated as a purely localised species. A linear increase is indeed predicted theoretically for delocalised X/sup -/. In addition, the observed temperature behaviour demonstrates that unlike the donor bound exciton to which X/sup -/ has been previously compared, X/sup -/ radiative recombination can take place with a specific strongly k dependent selection rule. The behaviour of X/sup -/ lifetime at the lower temperatures indicates the presence of a certain degree of localisation.
Keywords :
II-VI semiconductors; cadmium compounds; excitons; photoluminescence; radiative lifetimes; semiconductor quantum wells; time resolved spectra; 2 K; 200 ps; 30 K; 70 ps; CdTe; CdTe quantum wells; donor bound exciton; k dependent selection rule; localisation; localised species; negatively charged exciton; negatively charged excitons; picosecond photoluminescence; radiative lifetime; radiative lifetimes; radiative recombination; temperature dependence; Convolution; Excitons; Gaussian processes; Hall effect devices; Image retrieval; Laser transitions; Magnetic fields; Magnetic films; Optical pulses; Quantum well lasers;
Conference_Titel :
Quantum Electronics Conference, 2000. Conference Digest. 2000 International
Conference_Location :
Nice, France
Print_ISBN :
0-7803-6318-3
DOI :
10.1109/IQEC.2000.907875
