采用InGaAs或InAlAs缓冲层的高In组分InGaAs探测器结构材料特性

摘要

High indium content In0.78 Ga0.22As photodetector structures have been grown on InP substrates with Inx Ga1 -xAs or InxAl1 -xAs graded buffer layers wherein x changed continuously by gas source molecular beam epitaxy.Their characteristics were investigated by atomic force microscope,x-ray diffraction,transmission electron microscopy and photoluminescence.The differences between samples with the two kinds of buffer layers were studied.Results show that moderate surface morphology can be obtained with either InxGa1 -xAs or InxAl1 -xAs buffer layers.Larger residual strain is present in the photodetector structure with InxGa1 -xAs buffer layer.On the other hand,superior optical characteristics have been observed for the photodetector structure with Inx Al1 -xAs buffer layer.%利用气态源分子束外延在InP衬底上生长了具有InxGa1-xAs或InxAl1-xAs连续递变缓冲层的高In组分In0.78Ga0.22As探测器结构.通过原子力显微镜、X射线衍射、透射电子显微镜和光致发光对它们的特性进行了表征和比较.结果表明,具有InxGa1-xAs或InxAl1-xAs缓冲层的结构都能获得较平整的表面；具有InxGa1-xAs缓冲层的探测器结构表现出更大的剩余应力；具有InxAl1-xAs缓冲层的探测器结构所观察到的光学特性更优.