Effect Of In Variable Composition On Optical Properties Of GaN-Based Materials

In group ? nitride semiconductors,GaN-based materials are widely used in optoelectronic devices and high temperature,high frequency and high power devices due to their adjustable band gap and excellent optical and electrical properties.The luminescence process mainly depends on the energy band structure at K_point(k=0).The conduction band structure and valence band structure of wurtzite InGaN alloy are S-like orbitals and P-like orbitals respectively,their structure has some influence on the directivity of light.The first-principles calculation can effectively explain and predict the physical phenomena in the micro-system.In this paper,the first-principles-based calculation method is used in this paper to study the effects of the changes of In composition and lattice structure on the valence band structure and optical properties of GaN-based materials:1.Using the Material Studio material simulation software,the super-cell structure model of wurtzite InxGa1-xN material was established by doping on the basis of the original cell of GaN material.The In component x content of the In component was 0,0.25,0.5,0.75 and 1.Using VASP first-principles calculation software package to calculate the effect of different In composition on the valence band structure,total basic optical properties change,which is beneficial to the improvement of the light extraction efficiency at the wavelength of 200-400 nm.when the In component content is 0.75,the lattice structure change has the least influence on the optical properties of the InxGa1-xN materials.Therefore,the wurtzite InxGa1-xN material can obtain higher luminous efficiency in different bands of light by controlling the content of InxGa1-xN and using appropriate composition and structure.At the same time,in the study of InxGa1-xN materials,increasing the In-rich local states in the InxGa1-xN inhomogeneous distribution and reducing the electric field effect in the quantum wells are discussed.It provides a theoretical reference for further improving the light output efficiency.