Structural, electronic, and transport properties of Ge doped graphene: A DFT study

Using the study of first principles, the structural, electronic, and transport characteristics of a monolayer graphene supercell doped with germanium are investigated. The effect of dopant on the aforementioned properties is examined as the germanium concentration ranges from 12.5% to 25%. It has been observed that hetero atom-like germanium doping can increase the band gap in graphene, enhancing its potential use as a thermoelectric material. We observed the semiconducting and zero band gap semiconducting behaviour of graphene due to variations in doping concentration. It is found that the Seebeck coefficient of pure graphene (C8) is positive, While the doped graphene structures (C7Ge1, C6Ge2) have negative Seebeck coefficients. The ZT of pure graphene is very low, but ZT can be improved by doping the Ge atom to the graphene structure. Also, it is shown that the concentration of doping has a significant impact on the graphene's thermal conductivity. •Effect of germanium doping on graphene’s structural, electronic, and thermal transport properties.•Germanium doping in graphene opens up a band gap and also decreases its lattice thermal conductivity.•Enhances its applicability as a TE material.•A huge decrease in the thermal conductivity of germanium-doped graphene compared to pristine graphene.•The concentration of doping has a significant impact on the graphene's thermal conductivity.