超薄层AlGaAs样品的光调制反射谱研究

STUDY ON ULTRA THIN AlGaAs LAYER ON GaAs

用调制光谱的方法对分子束外延（ＭＢＥ）生长在ＧａＡｓ（１００）衬底上的一组超薄层本征型ＡｌｘＧａ１－ｘＡｓ层进行了原位的研究．对厚度在３５ｎｍ以下的一组样品观察到了若干个跃迁峰，而对厚度在１００ｎｍ的样品只观察到了一个跃迁峰．观察到的各峰随厚度的改变而变化．

A Series of samples of ultra thin AlGaAs films grown on GaAs(100) substrate by MBE are studied by photomodulated reflectance (PR)spectroscopy in ultra high vacuum chamber.More than one peak are observed for samples with thickness less than 35nm,but only one peak is observed for 100nm thick sample,The position and width of these peaks change with sample thickness.The experimental results are well explained by step potential model.