Hot carriers in a bipolar graphene

TL;DR

This paper models hot carrier dynamics in doped graphene under electric fields, considering energy relaxation, generation-recombination, and scattering, to analyze conductivity and regime transitions.

Contribution

It introduces a comprehensive model of hot carrier behavior in bipolar graphene, incorporating both intraband and interband processes with energy and concentration balance equations.

Findings

Current-voltage characteristics show nonlinear behavior.

Transition between bipolar and monopolar conductivity regimes is characterized.

Temperature and gate voltage significantly influence conductivity regimes.

Abstract

Hot carriers in a doped graphene under dc electric field is described taking into account the intraband energy relaxation due to acoustic phonon scattering and the interband generation-recombination transitions caused by thermal radiation. The consideration is performed for the case when the intercarrier scattering effectively establishes the quasiequilibrium electron-hole distributions, with effective temperature and concentrations of carriers. The concentration and energy balance equations are solved taking into account an interplay between weak energy relaxation and generation-recombination processes. The nonlinear conductivity is calculated for the momentum relaxation caused by the elastic scattering. The current-voltage characteristics, and the transition between bipolar and monopolar regimes of conductivity are obtained and analyzed, for different temperatures and gate voltages.