Theeffect of a stacking fault on the electronic properties of dopants ingallium arsenide

Abstract

We performed a theoretical investigation on the effects of extendeddefects on the structural and electronic properties of dopant atoms ingallium arsenide. We observed that silicon impurities segregate atGaAs stacking faults. A Si atom at a Ga site in a stacking faultin either a neutral or a negatively charged state is energeticallyfavourable as compared to a Si atom at a Ga site in a crystallineenvironment by as much as 0.2 eV. Additionally, a substitutional Siimpurity in the negative charge state in a stacking fault has adistinct structure as compared to the same impurity in acrystal. The results suggest that the stacking fault may prevent theformation of metastable defects, such as DX centres.