Electronic, optical and thermal properties of highly stretchable 2D carbon Ene-yne graphyne

Abstract: Recently, a new carbon-based two-dimensional (2D) material, so called "carbon Ene-yne" (CEY), was successfully synthesized. In this work, we examine electronic, optical and thermal properties of this novel material. We studied the stretchability of CEY via density functional theory (DFT) calculations. Using the PBE and HSE06 functionals, as well as the G$_0$W$_0$ method and the Bethe-Salpeter equation, we systematically explored electronic and optical properties of 2D CEY. In particular, we investigated the change of band-gap and optical properties under uniaxial and biaxial strain. Ab-initio molecular dynamics simulations confirm that CEY is stable at temperatures as high as 1500 K. Using non-equilibrium molecular dynamics simulations, the thermal conductivity of CEY was predicted to be anisotropic and three orders of magnitude smaller than that of graphene. We found that in the visible range, the optical conductivity under high strain levels is larger than that of graphene. This enhancement in optical conductivity may allow CEY to be used in photovoltaic cells. Moreover, CEY shows anisotropic optical responses for x- and y- polarized light, which may be suitable as an optical linear polarizer. The comprehensive insight provided by the present investigation should serve as a guide for possible applications of CEY in nanodevices.