Modeling of axial heterostructure formation in ternary III-V nanowires

Abstract

A model is proposed to depict the formation of axial heterostructure in ternary III-V nanowires (NW) grown by the catalytic vapor-liquid-solid (VLS) method. Our approach is based on the determination of chemical potential of a four-component liquid using the regular solution model and Stringfellow's scheme for the computation of the interaction coefficients of species present in the droplet. The model allows the estimation of the heterojunction width dependence on the growth temperature. This dependence has not been reported before by any previous theoretical studies. The AlGaAs/GaAs heterojunction formation in the Au-catalyzed AlGaAs NWs was considered as an example of ternary system. The heterojunction width was found to increase with the growth temperature with a second-order polynomial dependence.