標題: | Strain relaxation in InAs self-assembled quantum dots induced by a high N incorporation |
作者: | Chen, J. F. Yang, C. H. Wu, Y. H. Chang, L. Chi, J. Y. 材料科學與工程學系 電子物理學系 Department of Materials Science and Engineering Department of Electrophysics |
關鍵字: | deep levels;defect states;III-V semiconductors;indium compounds;internal stresses;nitrogen;self-assembly;semiconductor quantum dots;stress relaxation;transmission electron microscopy |
公開日期: | 15-十一月-2008 |
摘要: | The effect of a high N incorporation in self-assembled InAs quantum dots (QDs) is investigated by analyzing the electronic and structural properties around QD region. Capacitance-voltage profiling and admittance spectroscopy shows that N incorporation into the InAs QD layer leads to drastic carrier depletion in the QD layer and neighboring GaAs layers due to the formation of a deep defect state at 0.34-0.41 eV. The signature of this defect state is similar to those defects observed in strain relaxed QDs or InGaAs/GaAs quantum wells when the InAs deposition thickness exceeds a critical thickness. Accordingly, the N incorporation might result in strain relaxation either by increasing localized strain or by inducing composition inhomogeneities, which provide nucleation sources for strain relaxation. The argument of strain relaxation is supported by transmission electron microscopy that reveals lattice misfits at the QD layer and neighboring GaAs layers. |
URI: | http://dx.doi.org/10.1063/1.3028235 http://hdl.handle.net/11536/8143 |
ISSN: | 0021-8979 |
DOI: | 10.1063/1.3028235 |
期刊: | JOURNAL OF APPLIED PHYSICS |
Volume: | 104 |
Issue: | 10 |
結束頁: | |
顯示於類別: | 期刊論文 |