MBE生长ZnO薄膜的结构和光学特性的研究  

Structural and Optical Characterization of ZnO Thin Films Grown by Plasma-Assisted Molecular Beam Epitaxy

作　　者：蓝镇立[1] 张希清[1] 杨广武[2] 孙建[1] 刘凤娟[1] 黄海琴[1] 张蕊[3] 殷鹏刚[3] 郭林[3] 宋宇晨[4] 

机构地区：[1]北京交通大学光电子技术研究所,发光与光信息技术教育部重点实验室,北京100044 [2]天津工业大学理学院,天津300160 [3]北京航空航天大学材料科学与工程学院,北京100083 [4]丽水学院理学院,浙江丽水323000

出　　处：《光谱学与光谱分析》2008年第2期253-255,共3页Spectroscopy and Spectral Analysis

基　　金：国家“973”项目(2003CB314707);国家自然科学基金重点和面上项目(50532090,60476005);教育部留学基金项目资助

摘　　要：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 thin films were grown by plasma-assisted molecular beam epitaxy （P-MBE） on Al2O3 （0001） substrate with a low temperature ZnO buffer layer. Structural and optical characterization were studied for ZnO thin films. Only a peak at （0002） were observed in the X-ray reflectivity（XRD） spectra with the full-width at half maximum （FWHM） value 0. 18°, and two peaks 1LO（579cm^-1） and 2LO（1 152 cm^-1） were detected in the resonance Raman scattering spectra at room temperature. These results indicated that ZnO thin films had single orientation of c axis and high-quality of crystal wurtzite structure. The absorption of free-exciton and exciton-LO phonon appeared in the absorption spectra, which confirmed that the exciton state in the ZnO thin films were stable even at room temperature. And the energy spacing between these two peaks is 71.2 meV, corresponds to the longitudinal optical phonon energy of 71 meV of ZnO. Besides, from the photoluminescence spectra, no defect-related deep emission were observed, but just a remarkable free-exciton emission located at 376nm were obtained at room temperature, it proved that the ZnO thin films had high-quality but low density of defect.

关 键 词：ZNO薄膜 P-MBE 光致发光 RAMAN散射 

分 类 号：O433.4[机械工程—光学工程]