Carrier capture and relaxation in charged quantum dots triggered by vibrational relaxation
详细信息 查看全文
- 作者：A.M. Kechiantz ; K.W. Sun
- 关键词：Quantum dot ; Carrier capture
- 刊名：Physica E
- 出版年：2008
- 出版时间：January 2008
- 年：2008
- 卷：40
- 期：3
- 页码：668-673
- 全文大小：419 K
文摘
Local polarization and the strain of the crystal lattice around the charged quantum dot in semiconductors must vibrate to relax when the mobile carrier is captured by the dot and makes it uncharged. Triggered vibrations induce the sudden perturbation of electronic states in the quantum dot. The Hamiltonian of electron interaction with a local vibrating field and carrier capture time are calculated. It is shown that the principle of uncertainty has a strong influence on this effect. The calculated values of electron capture time are on a sub-picosecond timescale at a high pumping intensity, and are strongly dependent on the scale of quantum confinement. The calculations fit well with photoluminescence rising times τ=0.45 ps [K. Gündoğdu, K.C. Hall, T.F. Boggess, D.G. Deppe, O.B. Shchekin, Appl. Phys. Lett. 85 (2004) 4570.] and τ=1.7 ps [K.W. Sun, A. Kechiantz, B.C. Lee, C.P. Lee, Appl. Phys. Lett. 88 (2006) 163117.] which are observed in the experiments on p-doped InAs quantum dots.