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Title: Non-equilibrium Green's functions method: Non-trivial and disordered leads

The non-equilibrium Green's function algorithm requires contact self-energies to model charge injection and extraction. All existing approaches assume infinitely periodic leads attached to a possibly quite complex device. This contradicts today's realistic devices in which contacts are spatially inhomogeneous, chemically disordered, and impacting the overall device characteristics. This work extends the complex absorbing potentials method for arbitrary, ideal, or non-ideal leads in atomistic tight binding representation. The algorithm is demonstrated on a Si nanowire with periodic leads, a graphene nanoribbon with trumpet shape leads, and devices with leads of randomly alloyed Si{sub 0.5}Ge{sub 0.5}. It is found that alloy randomness in the leads can reduce the predicted ON-state current of Si{sub 0.5}Ge{sub 0.5} transistors by 45% compared to conventional lead methods.
Authors:
; ; ;  [1]
  1. Network for Computational Nanotechnology, Purdue University, West Lafayette, Indiana 47907 (United States)
Publication Date:
OSTI Identifier:
22392076
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 21; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALGORITHMS; GERMANIUM ALLOYS; GRAPHENE; GREEN FUNCTION; NANOSTRUCTURES; RANDOMNESS; SELF-ENERGY; SILICON; SILICON ALLOYS; TRANSISTORS