Density Functional Calculations for InxGa1-xAs Nanostructure

Abstract

The electrostatic and structural properties of InₓGa₁₋ₓAs nanocrystals were investigated withdensity functional theory (DFT) in conjunction with large unit cell (LUC). The calculations werecarried out for 16 and 64 atom nanocrystals with indium compositions of x = 0.00, 0.25, 0.50,and 1.00 in 3D periodic boundary condition. All the calculations were carried out on theB3LYP functional and 6-31G basis set with the assistance of Gaussian 09 software. The resultsdemonstrate that an increase in indium is accompanied by a systematical growth of the latticeconstants and a reduce in the electronic band gap, which is in agreement with quantumconfinement and the alloying effect. Other properties, such as the total and cohesive energies,electron affinity, ionisation energy and ionicity, also showed significant size-dependent andcomposition-dependent differences. The results indicate strong atomic-configuration dependentelectronic properties of the material that shed light on its potential application in nextgeneration nanoelectronics and photonics