Mechanisms of photocurrent generation in graphene, itsbilayer: established facts and open questions

On Wednesday, November 1 at 15:00, Moscow time, ACTP will hold the
seminar on "Mechanisms of photocurrent generation in graphene and its
bilayer: established facts and open questions" by Dmitry Svintsov, PhD.

Abstract

2d materials are considered as promising candidates for future
optoelectronic devices due to high carrier mobilities and strong,
usually broadband, absorption. Still, the principles of photocurrent
generation in 2d materials are largely a matter of debate. In this talk,
I will start with the discussion of the photo-thermoelectric effect in
graphene as a main mechanism of light detection. We will see why it
dominates over the 'conventional' splitting of electron-hole pairs be
built-in fields in 2d p-n junctions. Further on, I will present several
selected experimental results on infrared and terahertz detection in
graphene and its bilayer that do not fit into the established
thermoelectric picture. We shall discuss the anomalous
polarization-dependent photocurrent at 'metal-graphene' junctions, which
can switch from isotropic to anisotropic with varying the carrier
density. We shall also discuss the density- and temperature-dependent
photoresponse of p-n junctions in gapped graphene bilayer, and discuss
the limiting behavior of photocurrent at low temperatures and large
induced band gap.