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利用Raman显微镜系统对两块用MOCVD方法在Cd0 96Zn0 0 4 Te衬底上生长的Hg0 8Cd0 2 Te外延薄膜样品在光谱范围 5 0～ 5 0 0 0cm-1进行了测量 ,在其中的一块样品上首次发现了 1 4 3eV至 1 93eV范围内出现的具有周期结构的光致发光峰 ,该发光峰对应的能带中心位于Hg0 8Cd0 2 Te外延层导带底上方 1 73eV ,在另外一块外延薄膜样品中仅观察到四个Raman散射峰 ,没有周期结构的发光峰。为了分析上述光致发光的起因 ,对两块样品进行了X射线的双晶回摆曲线样品结构分析 ,得出样品在 1 4 3eV至 1 93eV范围的光致发光峰是由于改进MOCVD生长工艺提高了样品的结构质量所致 ,通过分析指出该光致发光峰是来源于Hg0 8Cd0 2 Te外延层中的阴性离子空位的共振能级。
Two samples of Hg0 8Cd0 2 Te epitaxial films grown on a Cd0 96 Zn0 4 Te substrate by MOCVD were measured in a spectral range of 50 ~ 500 cm-1 using a Raman microscope system. On one of the samples The photoluminescence peak with periodic structure appeared in the range of 143 eV to 1 93 eV for the first time. The center of the emission band corresponds to 1 73 eV above the bottom of the conduction band of the Hg0 8Cd0 2 Te epitaxial layer. In the other epitaxial film sample Only four Raman scattering peaks were observed, and there was no luminescence peak of the periodic structure. In order to analyze the cause of photoluminescence, the two samples were analyzed by X-ray double-crystal swing curve, and the photoluminescence peak of the sample in the range of 143eV to 193eV was obtained by the improvement of MOCVD growth process The structural quality of the samples was analyzed. It was pointed out that the photoluminescence peak was the resonant level derived from the vacancy of the negative ions in the epitaxial layer of Hg0 8Cd0 2 Te.