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用等离子体源辅助分子束外延(P-MBE)方法在蓝宝石(0001)面上生长出了高质量的ZnO薄膜,并对其结构和发光特性进行了研究。在XRD中只观察到ZnO薄膜的(0002)衍射峰,其半高宽(FWHM)值为0.18°;而在共振Raman散射光谱中观测到1LO(579cm-1)和2LO(1152cm-1)两个峰位,这些结果表明ZnO薄膜具有单一c轴取向和高质量的纤维锌矿晶体结构。在吸收光谱中观测到自由激子吸收和激子-LO声子吸收峰,这表明在ZnO薄膜中激子稳定的存在于室温,并且两峰之间能量间隔为71.2meV,与文献上报道的ZnO纵向光学声子能量(71meV)相符。室温下在光致发光光谱(PL)中仅观测到位于376nm处的自由激子发光峰,而没有观测到与缺陷相关的深能级发射峰,表明ZnO薄膜具有较高的质量和低的缺陷密度。
High quality ZnO films were grown on sapphire (0001) surface by plasma source assisted molecular beam epitaxy (P-MBE) and their structures and luminescent properties were studied. Only the (0002) diffraction peak of the ZnO thin film was observed by XRD, and its full width at half maximum (FWHM) was 0.18 °. In the resonance Raman scattering spectra, 1LO (579 cm -1) and 2LO (1152 cm -1) The results show that ZnO films have a single c-axis orientation and a high quality wurtzite crystal structure. Free exciton absorption and exciton-LO phonon absorption peaks were observed in the absorption spectra, indicating that the excitons are stable at room temperature in the ZnO thin film and the energy gap between the two peaks is 71.2 meV. Compared with the reported ZnO Longitudinal optical phonon energy (71meV) matches. Only the free exciton emission peak at 376 nm was observed in the photoluminescence spectrum (PL) at room temperature, while the defect-related deep level emission peak was not observed, indicating that the ZnO thin film has high quality and low defects density.