摘要
在室温下 ,运用反射椭偏光谱技术 ,对生长在砷化镓上的铝镓铟磷以及铝镓铟磷 (掺硅 )两样品进行了研究 .测得它们在可见光区的光学常数 ,求得吸收系数、介电函数随光子能量的变化关系 .对样品的介电函数虚部谱进行数值微分 ,得到它们的三级微商谱 .通过对样品的吸收系数谱和介电函数虚部的三级微商谱的分析 ,得到两样品的带隙Eg,Eg+Δ0 和Eg 以上成对结构跃迁的能量位置及间隔 .将Eg 和Eg+Δ0 的值与计算值和已发表的值比较 ,符合较好 ,但存在小的差异 .分析发现 ,样品存在有序结构是引起差异的主要原因 .根据椭偏测量的数据 ,用有效介质近似理论计算了样品中铝的组分 ,并与X射线微区分析的测量结果加以比较 ,二者一致 .
AlGaInP and that doped Si grown on the GaAs substrates were studied by using the reflection ellipsometric spectroscopy at room temperature. Optical constants for two samples were measured in the visible light region. Dependence of the absorption coefficients and dielectric functions on the photon energy was obtained for two samples. The third derivative spectra of the imaginary part of dielectric functions for two samples were evaluated by the numerical differentiation. The band gaps E g, E g+Δ 0 and the gap of the paired structure above E g were gained by analyzing the above spectra respectively. The values of E g and E g+Δ 0 were in agreement with the theoretical and published data,but there was a certain difference between them. Moreover, it was found the main reason of causing difference was the existence of ordered structure of two samples. In addition, the Al contents of the samples were calculated by means of effective medium approximation theory, and the results were consistent with that obtained by the energy dispersive X-ray analysis.
出处
《山东大学学报（理学版）》
CAS
CSCD
北大核心
2002年第4期324-328,共5页
Journal of Shandong University(Natural Science)
基金
"8 6 3"计划资助项目 ( 86 3 -71 5 -0 0 1 -0 1 71 )
山东大学青年科学基金资助项目 .
