Photoreflectance optimization: A comparison between monochromator and glass filters for photoluminescence and laser light elimination
Photoreflectance optimization: A comparison between monochromator and glass filters for photoluminescence and laser light elimination
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DOI：
10.1063/1.1141359
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发表时间：
1990-09
影响因子：
1.6
通讯作者：
A. Giordana;R. Glosser
中科院分区：
文献类型：
--
作者：
A. Giordana;R. Glosser
本文评估了一种光反射装置，其中不需要的光致发光和激光从信号中分离的单色器放置在前面的检测器相比，分离更常用的玻璃过滤器。我们目前的结果，从这两种技术的应用研究的3.4-和4.3-eV的结构，在体硅和硅膜上的蓝宝石，1.4-eV的结构在GaAs中，和1.8-eV的结构的Al0.33Ga0.77As。用第二单色器代替玻璃滤光器，除了允许更好地抑制杂散光之外，还扩展了可以获得令人满意的光反射信号的波长范围，并允许观察更接近调制激光线的信号。另一方面，对于高激光功率，对于低光栅效率区域中的弱信号，或者仅仅出于经济原因，玻璃滤光器的使用可能是优选的。
This article evaluates a photoreflectance apparatus in which unwanted photoluminescence and laser light are separated from the signal by a monochromator placed in front of the detector as compared to separation by the more commonly used glass filters. We present results from the application of both techniques to the study of the 3.4‐ and 4.3‐eV structures in both bulk silicon and silicon films on sapphire, the 1.4‐eV structure in GaAs, and the 1.8‐eV structure of Al0.33Ga0.77As. The replacement of glass filters with a second monochromator, in addition to allowing a better rejection of spurious light, extends the range of wavelengths in which a satisfactory photoreflectance signal can be obtained and permits observation of a signal closer to the modulating laser line. On the other hand the use of glass filters can be preferable for high laser power, for weak signals in regions of low grating efficiency, or merely for economical reasons.