專題演講 Seminar

2017/01/06(Fri)     10:30 -12:00    五樓第一會議室 5F, 1st Meeting Room

Title

Carrier Delocalization in 2-Dimensional Coplanar p-n Junctions of Graphene and Metal Dichalcogenides

Speaker

俞紹安 先生 (萊斯大學應用物理學系)

Mr. Henry (Shan-An) Yu (Applied Physics, Rice University)

Abstract

With lateral coplanar heterojunctions of two-dimensional monolayer mate-
rials turning into reality, the quantitative understanding of their electronic,
electrostatic, doping, and scaling properties becomes imperative. In contrast
to traditional bulk 3D junctions where carrier equilibrium is reached through
local charge exchange, a highly non-localized charge transfer (trailing o as
1=x away from the interface) is present in lateral 2D junctions, increasing the
junction size considerably. The depletion width scales as p^-1, while the dif-
ferential capacitance varies very little with the doping level p. The properties
of lateral 2D junctions are further quanti ed through numerical studies of re-
alistic materials, with graphene, MoS2 and their hybrid serving as examples.
Careful analysis of the built-in potential pro le across the heterojunction
shows strong reduction of Fermi level pinning, suggesting better control of
the barrier in 2D metal-semiconductor junctions.

Language

演講語言 (Language): in English