| Summary: | 碩士 === 國立中央大學 === 物理學系 === 105 === In this work, we measured the photoluminescence spectra and Raman spectra to analyze the optical properties and phonon behaviors of Zn1-xCdxO (x = 0%, 9%, 14%, 17%, 20%) and Zn1-xMgxO (x = 0%, 3.8%, 11.5%, 13.2%).
Zinc oxide (ZnO) with different content Mg or Cd incorporation is one of methods to tune bandgap and emission wavelength, but also one of reasons to make PL signal broadening. From temperature dependent PL spectra, the localized states in Zn1-xCdxO and Zn1-xMgxO were observed and there will be an anomalous blue shift in its temperature dependent PL peak. Then, Eliseev’s model can be used to realize the dispersive energy of the localized state.
From our Raman spectra, by Cd (Mg) incorporation, LO phonon signal peak position is red-shifting (blue-shifting) and phonon signal peak shape is broadening and becoming asymmetric. This is described that the disorder of lattice vibration and there exists the confinement effect which leads to a relaxation of the q=0 selection rule. In this essay, we compare experimental value of Raman peak shift and asymmetric Raman peak shape with theoretical value calculated by MREI model and spatial correlation model.
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