Si/SiGe quantum-cascade emitters for terahertz applications
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- 作者：Paul ; D.J. ; Lynch ; S.A. ; Bates ; R. ; Ikonic ; Z. ; Kelsall ; R.W. ; Harrison ; P. ; Norris ; D.J. ; Liew ; S.L. ; et. al.
- 关键词：78.30 ; 78.50.Ge ; 78.60.Fi ; 42.72.A ; Si/SiGe ; Intersubband ; Electroluminescence ; Quantum cascade
- 刊名：Physica E
- 出版年：2003
- 出版时间：January, 2003
- 年：2003
- 卷：16
- 期：1
- 页码：147-155
- 全文大小：555 K
文摘
The quantum cascade laser provides one possible method of realizing high efficiency light emission from indirect band gap materials such as silicon. Strain-symmetrized Si/SiGe samples designed to investigate the intersubband properties of quantum wells are examined. Electroluminescence data from Si/SiGe quantum-cascade staircases demonstrating edge emission from heavy-hole to heavy-hole transitions and light-hole to heavy-hole transitions are presented. In surface-normal emission only light-hole to heavy-hole electroluminescence is observed at 2.9THz (103μm wavelength) as predicted by theory. Modulation-doped SiGe quantum well samples are also investigated to determine the underlying physics in the system. Results of picosecond time resolved studies of the dynamics of the intersubband transitions using a free electron laser are presented which show approximately constant relaxation times of 10ps below 100K.