標題: | Thickness-dependent lattice relaxation and the associated optical properties of ZnO epitaxial films grown on Si (111) |
作者: | Liu, W. -R. Lin, B. H. Kuo, C. C. Lee, W. C. Hong, M. Kwo, J. Hsu, C. -H. Hsieh, W. F. 光電工程學系 Department of Photonics |
公開日期: | 2012 |
摘要: | The evolution of the strain state as a function of layer thickness of (0001) oriented ZnO epitaxial films grown by pulsed-laser deposition on Si (111) substrates with a thin oxide Y2O3 buffer layer was investigated by high resolution X-ray diffraction (XRD). The ZnO layers experience a tensile strain, which gradually diminishes with increasing layer thickness. Regions with a nearly strain-free lattice develop as the layer thickness exceeds a critical value and are correlated with the emergence of the < 11 (2) over bar0 > oriented crack channels. The influence of the biaxial strain to the vibrational and optical properties of the ZnO layers were also studied by micro-Raman, optical reflectance, and photoluminescence. The deformation-potential parameters, a(lambda) and b(lambda), of the E-2(high) phonon mode are determined to be -740.8 +/- 8.4 and -818.5 +/- 14.8 cm(-1), respectively. The excitonic transitions associated with the FXA, FXB, and D degrees X-A emissions and the A-exciton binding energy all show linear dependence on the in-plane strain with a negative slope. |
URI: | http://hdl.handle.net/11536/20500 http://dx.doi.org/10.1039/c2ce26074c |
ISSN: | 1466-8033 |
DOI: | 10.1039/c2ce26074c |
期刊: | CRYSTENGCOMM |
Volume: | 14 |
Issue: | 23 |
起始頁: | 8103 |
結束頁: | 8109 |
顯示於類別: | 期刊論文 |