Abstract
The correlation between the exciton-phonon interaction and the electrical transport property for the as-grown and annealed ZnO epilayers were investigated. From fitting of the Bose-Einstein approximation using emission parameters extracted from temperature-dependent photoluminescence spectra, it was found that the strength of exciton-phonon coupling in the annealed ZnO epilayers is stronger than that in the as-grown ZnO epilayer. For Raman scattering and Hall-effect measurements, the increase in exciton-phonon coupling for the annealed ZnO epilayer was confirmed to be attributed to lattice asymmetry-induced phonon scattering due to the increase in free electrons. The increase in free electrons for the annealed ZnO epilayer is considered as resulting from the increase in deformation potential for negatively charged native point defects in the unintentionally doped ZnO epilayer.
Original language | English |
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Article number | 093515 |
Journal | Journal of Applied Physics |
Volume | 104 |
Issue number | 9 |
DOIs | |
State | Published - 2008 |