Spin Phenomena of CdZnSe Self-assembled Quantum Dots Investigated by Magneto-photoluminescence
Spin Phenomena of CdZnSe Self-assembled Quantum Dots Investigated by Magneto-photoluminescence
- 주제(키워드) Self-assembled quantum dot , Spin relaxation , Polarization
- 발행기관 한국물리학회
- 발행년도 2009
- 총서유형 Journal
- UCI G704-000411.2009.55.1.051
- KCI ID ART001498104
- 본문언어 영어
초록/요약
Magneto-photoluminescence (PL) experiments were carried out on a self-assembled CdZnSe/ZnSe quantum dot (QD) system. The intensities of the PL peak exhibited significant differences for the two circular polarizations when a magnetic field was applied. A simple two-level rate equation model, including the spin flip time τ s and the exciton recombination time τ r , was used to analyze the observed degree of the polarization in the polarization selective PL measurements. Specifically, the magnetic field dependence of the polarization was fitted by treating τ s/τ r as a fitting parameter in the model. The best fitting was obtained with the value of τ s/τ r ~ σ, indicating that the spin relaxation time is much longer than the exciton recombination time. Such polarization selective PL measurements were further performed at several different temperatures, which showed a systematic decrease in the degree of polarization with increasing temperature.
more