Energy Band and Absorption Coefficient of Quantum Dots in a Well Structure |
| P. Zhang, X.-C. Lu, C.-L. Zhang and J.-H. Yao
Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, School of Physics, and TEDA Applied Physics School, Nankai University, Tianjin 300457, P.R. China |
| Received: December 18, 2011; In final form: April 15, 2012 |
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| Building on the effective-mass envelope function theory, this paper focuses on the study of the energy band and the absorption coefficient of InAs/-InxGa1 - xAs quantum dots in a well (DWELL) structure. In contrast to InAs/-In0.15Ga0.85As quantum DWELL, the InAs/-In0.2Ga0.8As quantum DWELL has lower ground states. With the thickness of In0.15Ga0.85As layer changing from 7 nm to 9 nm and In0.2Ga0.8As layer changing from 9 nm to 12 nm, the calculation shows that their absorption coefficient spectra takes a red shift in the long-wave infrared and far-infrared ranges, respectively. Moreover, when the thickness of the InxGa1 - xAs layer is defined as 9 nm, the absorption coefficient spectra of InAs/-In0.2Ga0.8As DWELL shows a obvious red shift comparing with that of InAs/-In0.15Ga0.85As DWELL. |
| DOI: 10.12693/APhysPolA.122.197 PACS numbers: 73.21.La, 73.63.Kv |