Phonon scattering channel and electrical transport of graphene induced by the anharmonic phonon renormalization

Using full electron-phonon interactions and the Boltzmann transport equation, the phonon scattering channel and electrical properties of graphene are investigated under anharmonic phonon renormalization (APRN). After the anharmonic phonon renormalization is considered, both phonon frequency and three-phonon phase space become small with the temperature. Meanwhile, the APRN has a greater effect on the acoustic branch and little effect on the optical branch. When three-phonon scattering is considered, the corresponding thermal conductivity is 3518 W/mK (300 K), 1900 W/mK (500 K), and 1122 W/mK (800 K), respectively. After four-phonon scattering is considered, the thermal conductivity of graphene decreases to 1844 W/mK at 300 K, 900 W/mK at 500 K, and 600 W/mK at 800 K, respectively. For three-phonon scattering, the primary scattering channels include ZA + TA -> ZO, TA + TA -> ZA, LA + LA -> ZO, ZA/TA -> TA + LA, LA/ZO -> ZO + TA, TO -> ZA + LA and LO -> ZO + LA. About the four-phonon scattering channel, the main contributions originate from X + ZA -> ZA + ZA, X + ZA/ZO -> ZA + ZO, and X + TA -> LA + ZO. The anharmonic phonon renormalization enlarges the strength of electron-phonon coupling, leading to the increase of n-type electric resistance from 24 omega to 26 omega at room temperature. This work gives insight into the phonon scattering channel and electrical property via anharmonic phonon renormalization in which normal processes dominate the ph-ph scattering.