A Thermodynamic Model of Diameter- and Temperature-dependent Semiconductor Nanowire Growth

Creating and manipulating nanowires (NWs) with controllable growth direction and crystal orientation is important to meeting the urgent demands of emerging applications with designed properties. Revealing the underlying mechanisms of the experimentally demonstrated effects of NW diameter and growth temperature on growth direction is crucial for applications. Here, we establish a thermodynamic model to clarify the dependence of NW growth direction on diameter and temperature via the vapor-liquid-solid growth mechanism, enabling analysis of NW critical length between unstable and stable states. At a small critical length, NWs with a large diameter or grown at low temperature tend to grow along the <111> direction, while at a large critical length, NWs with a small diameter or grown at high temperature favor the <110> direction. Specific growth parameters of ZnSe NW have been obtained which can guide the design of functional NWs for applications.