Theoretical prediction of a graphene-like structure of indium nitride: A promising excellent material for optoelectronics

Indium nitride is a very important solid state light material. Here we theoretically predict a planar graphene-like structure namely g-InN monolayer. We investigate its the mechanical, dynamical and thermal stabilities and structural, electronic, thermal, and mechanical properties via first-principles calculations. The electronic band structure shows that the g-InN monolayer possesses a direct band gap of 0.57 eV. The analysis of its partial electron density of state reveals that the Nitrogen 2/3, electrons and Indium 5s electrons are critical in forming this electronic band gap. The phonon band structure indicates that the plane structure is dynamically stable. Ab initio molecular dynamics simulations imply its thermal stability up to 600 K. We obtained the Helmholtz free energy, entropy, and heat capacity at constant volume of g-InN monolayers as a function of temperature up to 600 K. The Debye temperature is 290.92 K. The g-InN has a low in-plane stiffness, and a high Poisson ratio of 0.586. The potential profiles and the stress-strain curves indicate that the free standing g-InN monolayers can sustain large tensile strains, up to 0.13, 0.21, and 0.15 for armchair, zigzag, and biaxial deformations, respectively. Our results imply that g-InN monolayers are excellent optoelectronics materials and mechanically, dynamically, and thermodynamically stable, suggesting that it is promising to fabricate it in near future. Our predicted elastic limits could provide a safe-guide for strain-engineering the g-InN based electronic devices. (C) 2017 Elsevier Ltd. All rights reserved.