skip to main content

Title: Quantum calculations of the carrier mobility: Methodology, Matthiessen's rule, and comparison with semi-classical approaches

We discuss carrier mobilities in the quantum Non-Equilibrium Green's Functions (NEGF) framework. We introduce a method for the extraction of the mobility that is free from contact resistance contamination and with minimal needs for ensemble averages. We focus on silicon thin films as an illustration, although the method can be applied to various materials such as semiconductor nanowires or carbon nanostructures. We then introduce a new paradigm for the definition of the partial mobility μ{sub M} associated with a given elastic scattering mechanism “M,” taking phonons (PH) as a reference (μ{sub M}{sup −1}=μ{sub PH+M}{sup −1}−μ{sub PH}{sup −1}). We argue that this definition makes better sense in a quantum transport framework as it is free from long range interference effects that can appear in purely ballistic calculations. As a matter of fact, these mobilities satisfy Matthiessen's rule for three mechanisms [e.g., surface roughness (SR), remote Coulomb scattering (RCS) and phonons] much better than the usual, single mechanism calculations. We also discuss the problems raised by the long range spatial correlations in the RCS disorder. Finally, we compare semi-classical Kubo-Greenwood (KG) and quantum NEGF calculations. We show that KG and NEGF are in reasonable agreement for phonon and RCS, yet not formore » SR. We discuss the reasons for these discrepancies.« less
Authors:
; ;  [1] ;  [2] ; ;  [3]
  1. L-Sim, SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble (France)
  2. CEA, LETI-MINATEC, Grenoble (France)
  3. ST Microelectronics, Crolles (France)
Publication Date:
OSTI Identifier:
22278125
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CARBON; CARRIER MOBILITY; COMPARATIVE EVALUATIONS; CORRELATIONS; COULOMB SCATTERING; GREEN FUNCTION; INTERFERENCE; MATTHIESSEN RULE; PHONONS; QUANTUM WIRES; ROUGHNESS; SILICON; SURFACES; THIN FILMS