三五族相關材料之拉曼分析

Abstract

chapter 1, we will first discuss the development of Raman scattering and its basic theory. Further, the spacial correlation model which is used in the this chapter to realize the characterization of AlInGaP thin films will be performed. And about the thin films, two series of (AlxGa1-x)0.5In0.5P films were grown on lattice-matched GaAs by low pressure metalorganic chemical vapor deposition under different conditions and studied by Nomarski microscopy (NM), atomic force microscopy (AFM), photoluminescence (PL) and Raman scattering. NM and AFM images show cross-hatch patterns, related to dislocations and lattice mismatch, from one set of samples, but none from another set of films. Comparative PL and Raman measurements and analyses indicated the correlation between surface and optical properties. The degree of variations in compositions and film quality with the growth conditions were found from the spectral analyses. Raman spectral features are more sensitive to the sample growth parameter variations. The line shape analysis of line width, integrated intensity ratio and spacial correlation model fittng leads to information about the order of the sample crystalline quality. And comparison of these measurement results, the results from spacial correlation model analysis will be identified with the others. Accordingly, this method is more convenient method to characterize the crystalline quality. chapter 2, we will discuss the electronic Raman scattering based on the LO phonon-plasmon interaction effect, and first interpret the motivation and relative application. Furthermore, since the scattering theory is very miscellaneous, the theory from the fundamental to the forming model will be completely performed. Under different considerations, the mechanisms here will focus on the charge density fluctuation, deformation-optical and electro-optical effect and their perturbed result. After the basic theory, the simulation on the GaN and InN material will be also performed and separately predict the both wave vector dependent (long wave length) and wave vector nonconservation effect. We have prepared the Hall measured data of GaN samples to be a contrast and compare with the simulation results respectively. Likewise, the simulation results of the wave vector nonconservation are very unusual to the other published papers but consisted to the basic theory. Accordingly, we will comment on these papers (provide 3 Physical Review B papers). Finally, we will use these points to reform another reasonable model so that the more accurate recursive data to the Hall measurement could be obtained. The result consists with our points.