| Summary: | 碩士 === 淡江大學 === 物理學系碩士班 === 96 === The electronic structures and optical properties of various sizes of ZnO quantum dots (QDs) were studied using x-ray absorption, photoluminescence and Raman spectroscopy. The increase in the intensity ratio of the first-order Raman spectra of longitudinal optical (1LO) modes and their overtones (2LO), such as 2LO/1LO, which is related to the strength of Electron-Phonon Coupling (EPC), increased with the size of the QDs. This EPC behavior is also associated with the O K-edge x-ray absorption near-edge structure which increase with the intensity ratio of the O 2pπ(Iπ) and 2pσ(Iσ) orbitals as the sizes of the QDs increased, suggesting that the c-axis of the wurtzite ZnO QDs is the unique axis in the dipole transition.
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