Investigation on the Temperature and Size Dependent Mechanical Properties and Failure Behavior of Zinc Blende (ZB) Gallium Nitride (GaN) Semiconducting Nanowire

Abstract

The mechanical properties of Gallium Nitride (GaN) nanowire has drawn considerable attention of researchers due to its application as electronic and semiconducting material. It has been successfully deployed in LEDs, transistors, Radars, Li-Fi communication system and many other electronic devices. In this research work, Molecular Dynamics simulations have been performed to explore the temperature-dependent mechanical properties of Zinc-Blende (ZB) GaN nanowire for tensile simulation. Stillinger-Weber (SW) potential has been employed to define the inter-atomic interactions between atoms in the GaN crystal. The temperature has been varied from 100K-600K and corresponding mechanical properties have been reported. To explore the nanowire size effect on the mechanical properties, the cross-sectional area of the nanowire has been varied for the temperature of 300K. Investigations suggest that increment of temperature results in the failure of GaN nanowire at a lower value of stress 37.96 GPa to 30.06 GPa and corresponding Young's Modulus decreases as well. We have calculated ultimate tensile stress and Young's modulus as 36.2 GPa and 189.3 GPa respectively at 300K for 13.37 nm2GaN nanowire. Our simulations results show that size has a significant effect on ultimate tensile stress and Young's Modulus of GaN nanowire. It has been found that as cross-sectional area increases both ultimate tensile stress and Young's modulus increases. Finally, the fracture behavior of GaN nanowire has also been reported from the atomistic simulation results. It has been found that 13.37 nm2GaN nanowire failed by creating a fracture plane along <111> direction of the nanowire axis and indicates the brittle nature of GaN nanowire.