Electron-phonon scattering limited intrinsic electrical conductivity of metallic MXenes X <sub>2</sub> C (X= Ti or Mo)
Ziang Jing, Jingya Liu, Nan Li, Hongwei Wang, Kai Wu, Yonghong Cheng, Bing Xiao
Abstract
Abstract The electron-phonon (e-p) scattering mechanism in two metallic MXenes (Ti 2 C and Mo 2 C) are investigated using the advanced Wannier-Fourier interpolation scheme. It is found that for both MXenes, the strongly interacting phonons with electrons are mainly attributed to the transverse and longitudinal optical modes (TO + LO). Among acoustic phonon branches, longitudinal acoustic mode exhibits higher coupling strength than either flexural mode or transverse mode. The predicted total e-p coupling of Ti 2 C (0.280) is smaller than that of Mo 2 C (0.926). The e-p coupling mechanism in Ti 2 C or Mo 2 C is different from graphene, but similar to that of transition-metal dichalcogenides. For the electronic band dispersion most adjacent to Fermi level, we predict the mean electron linewidths of 16.4 meV for Ti 2 C and 14.3 meV for Mo 2 C. Using the Ziman formula, the electrical conductivities of Ti 2 C and Mo 2 C at 300 K are found to be 5.497 × 10 4 S cm −1 for Ti 2 C and 1.593 × 10 4 S cm −1 for Mo 2 C with the associated relaxation times 90 fs and 185 fs, respectively. Our calculations indicate that the overall electrical conductivity is determined by both of the e-p coupling and electron concentration in metallic MXenes.