Photoconductivity of an intrinsic graphen

TL;DR

This paper investigates how intrinsic graphene's electrical conductivity changes under infrared light at low temperatures, highlighting the roles of electron-hole pair excitation, thermal processes, and phonon interactions.

Contribution

It presents a model that incorporates excitation, recombination, and relaxation processes specific to massless carriers in graphene, revealing a low threshold for nonlinear photoconductivity response.

Findings

Photoconductivity is influenced by the interplay of energy relaxation and recombination.

The nonlinear response threshold in graphene is relatively low.

The model accounts for acoustic phonon scattering and thermal radiation effects.

Abstract

We examine the photoconductivity of an intrinsic graphene associated with far- and mid-infrared irradiation at low temperatures. The model under consideration accounts for the excitation of the electron-hole pairs by incident radiation, the interband generation-recombination transitions due to thermal radiation, and the intraband energy relaxation due to acoustic phonon scattering. The momentum relaxation is assumed to be caused by elastic scattering. The pertinent collision integrals are adapted for the case of the massless energy spectrum of carriers that interact with the longitudinal acoustic mode and the thermal radiation. It is found that the photoconductivity is determined by an interplay between weak energy relaxation and generation-recombination processes. Due to this the threshold of nonlinear response is fairly low.