Strain Relaxation And Electronic Structure Of Nano Heterostructure

Nano optoelectronic materials and devices have a bright propect in the future in semiconductor industry. How to manufacture efficient, controllable and non-defective semiconductor nano-heterostructure material is a key issue in nanoelectronics research. In this paper, from the strain relaxation mechanism of nano-heterogeneous materials, combining with the finite element method and mobile asymptote optimization method, we accuratelly quantitative analysis of the physical properties of materials, such as stress and strain, equilibrium composition distribution and electronic structure.This paper relies on national natural fund project (Project name:study of one-dimensional semiconductor nanostructures growth mechanism), focus on growth mechanism and structural properties of semiconductor nanomaterials, the main content and innovations are as follows:1. Using KP theory combining with finite element method, investigate the effect of wetting layer in InAs/GaAs quantum dot, including strain distribution and electronic structure. Four different kinds of shape of InAs/GaAs quantum dots, which are observed in the experiment, are established. We quantitatively calculate the stress and strain, band edge as well as electronic structure with different thickness of wetting layer thickness on different shapes InAs/GaAs quantum dots. Further, as described in the consolidated results, we conclude that wetting layer thickness of0.5nm is the most suitable thickness for the InAs/GaAs quantum dots system.2. In the framework of continuous elasticity theory, using finite element method combining with method of moving asymptote, simulate the non-equibrilim composition distribution of GaN/InGaN core-shell nanowire. We firstly propose optimized the composition distribution by considering the Gibbs free energy. Our simulation results match well with the photoluminescence spectra in experiment, and it testifies the starin relaxation mechanism in the dominant position in composition distribution of cross-sectional of the nanowires.