Tailoring Electronic Properties of 6H‐SiC with Different Composition of Silicon by First‐Principles Calculations

Abstract

Silicon carbide (SiC) is used in a variety of applications including photovoltaic due to its high stability. The wide bandgap of SiC limits these applications and necessitates bandgap tuning toward lower energy for efficient solar absorption. In this regard, the electronic properties of highly stable SiC polytype 6H‐SiC are studied by first‐principles calculations. By varying the Si composition of 6H‐SiC the electronic properties are tailored. The calculated results show that increasing the Si composition of 6H‐SiC from 50% to 66.66% reduces the bandgap from 2.98 to 1.54 eV. It is observed that this reduction in bandgap occurs due to the addition of extra Si s/p orbitals which close the conduction band and valance band. From the electronic conductivity calculations, it is found that with increasing Si composition of 6H‐SiC the conductivity is improved due to higher hole density which can be verified by the spectrum peaks shifted toward near‐infrared and visible region.