L.L. Li 1, W. Xu 1,3, Z. Zeng 1, and Y.L. Shi 2
1 Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
2 Kunming Institute of Physics, Kunming, China and
3 Terahertz Research Center, University of Electronic Science and Technology, Chengdu 610054, China
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Abstract: We demonstrate theoretically that it is possible to realize terahertz (THz) fundamental band-gap between the electron mini-band in the InAs layer and the heavy-hole mini-band in the GaSb layer in InAs/GaSb based type II superlattices (SLs). The THz band-gap can be tuned by varying the sample growth parameters such as the well widths of the InAs and/or GaSb layers. The presence of such band-gap can result in a strong cut-off of optical absorption at THz frequencies. For typical sample structures, the THz cut-off of the optical absorption depends strongly on temperature and a sharper cut-off can be observed at relatively high-temperatures. This study is pertinent to the application of InAs/GaSb type II SLs as THz photodetectors. PACS numbers: 72.80.Cw, 72.20.Dp, 73.61.Cw
Keywords: THz band-gap, InAs/GaSb, typesuperlattices(SLÅs) , THz photodetectors.
Acknowledgments: This work was supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China.
Cite this article:
L.L. Li, W. Xu, Z. Zeng, and Y.L. Shi. Terahertz band-gap in InAs/GaSb type II superlattices[J]. International Journal of Terahertz Science and Technology, 2008, Vol.1, No.4: 207-220. DOI:10.11906/TST.207-220.2008.12.17