Band-gap tuning and optical response of two-dimensional SixC1-x: A first-principles real-space study of disordered two-dimensional materials
AbstractWe present a real-space formulation for calculating the electronic structure and optical conductivity of random alloys based on Kubo-Greenwood formalism interfaced with augmented space recursion technique [Mookerjee, J. Phys. C 6, 1340 (1973)JPSOAW0022-371910.1088/0022-3719/6/8/003] formulated with the tight-binding linear muffin-tin orbital basis with the van Leeuwen–Baerends corrected exchange potential [Singh, Harbola, Hemanadhan, Mookerjee, and Johnson, Phys. Rev. B 93, 085204 (2016)2469-995010.1103/PhysRevB.93.085204]. This approach has been used to quantitatively analyze the effect of chemical disorder on the configuration averaged electronic properties and optical response of two-dimensional honeycomb siliphene SixC1-x beyond the usual Dirac-cone approximation. We predicted the quantitative effect of disorder on both the electronic structure and optical response over a wide energy range, and the results are discussed in the light of the available experimental and other theoretical data. Our proposed formalism may open up a facile way for planned band-gap engineering in optoelectronic applications.