Seminar "Theory of thermionic emission from two-dimensional conductors"
Titiel: "Theory of thermionic emission from two-dimensional conductors"
Speaker: Dr. Maxim Trushin, Centre for Advanced 2D Materials, NUS, Singapore
The standard theory of thermionic emission developed for three-dimensional (3D) conductors does not apply to two-dimensional (2D) materials even for making qualitative predictions because of the vanishing out-of-plane quasiparticle velocity . Here, we focus on two mechanisms possibly responsible for out-of-plane electron transport in 2D-3D and 2D-2D heterojunctions. First, we consider the fundamental origin of the out-of-plane charge carrier motion in a perfect 2D conductor due to the finite quasiparticle lifetime and huge uncertainty of the out-of-plane momentum. The theory is applied to a Schottky junction between graphene and a bulk semiconductor to derive a thermionic constant, which, in contrast to the conventional Richardson constant, depends on the barrier height and Fermi level . Second, we focus on electron transport from a 2D conductor to a 2D semiconductor assuming some short-range interface disorder that results in momentum randomization and interlayer hopping. The model is applied to electron transport in graphene-MoS2 heterostructures .
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