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Title: Electrostatic screening near semiconductor surfaces

Abstract

We have developed a semimicroscopic theory for the electrostatic potential due to an isolated charge near a semiconductor surface whose surface states do not contribute free carriers. It employs the linearized version of the Debye-Hueckel (or, equivalently, the Thomas-Fermi) approximation. This includes the screening effects both of the plasma of free carriers due to bulk donors or acceptors, and of the bound polarizable charge associated with the bulk dielectric, but does not include free charge from intrinsic or extrinsic surface states. Results are obtained for a source charge above the semiconductor, within the semiconductor, and on the semiconductor surface, but we emphasize the last case. Although there is a dipole moment associated with source charge on the surface, the surface potential at long distances is quadrupolar; at intermediate distances greater than a characteristic atomic dimension it is a screened exponential, with screening length equal to the bulk value. The case of intermediate distance provides a rigorous basis for the exponentially screened surface potential commonly employed to analyze scanning tunneling microscopy images of the depletion or accumulation regions surrounding isolated charges on III-V(110) cleavage surfaces. Certain of these results also apply to colloids. (c) 2000 The American Physical Society.

Authors:
 [1];  [1];  [1]
  1. Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States)
Publication Date:
OSTI Identifier:
20216562
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 61; Journal Issue: 20; Other Information: PBD: 15 May 2000; Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; SURFACES; SEMICONDUCTOR MATERIALS; SCREENING; ELECTROSTATICS; THOMAS-FERMI MODEL; SOLID-STATE PLASMA; ELECTRIC CHARGES; DEPLETION LAYER; THEORETICAL DATA

Citation Formats

Krcmar, Maja, Saslow, Wayne M., and Weimer, Michael B. Electrostatic screening near semiconductor surfaces. United States: N. p., 2000. Web. doi:10.1103/PhysRevB.61.13821.
Krcmar, Maja, Saslow, Wayne M., & Weimer, Michael B. Electrostatic screening near semiconductor surfaces. United States. doi:10.1103/PhysRevB.61.13821.
Krcmar, Maja, Saslow, Wayne M., and Weimer, Michael B. Mon . "Electrostatic screening near semiconductor surfaces". United States. doi:10.1103/PhysRevB.61.13821.
@article{osti_20216562,
title = {Electrostatic screening near semiconductor surfaces},
author = {Krcmar, Maja and Saslow, Wayne M. and Weimer, Michael B.},
abstractNote = {We have developed a semimicroscopic theory for the electrostatic potential due to an isolated charge near a semiconductor surface whose surface states do not contribute free carriers. It employs the linearized version of the Debye-Hueckel (or, equivalently, the Thomas-Fermi) approximation. This includes the screening effects both of the plasma of free carriers due to bulk donors or acceptors, and of the bound polarizable charge associated with the bulk dielectric, but does not include free charge from intrinsic or extrinsic surface states. Results are obtained for a source charge above the semiconductor, within the semiconductor, and on the semiconductor surface, but we emphasize the last case. Although there is a dipole moment associated with source charge on the surface, the surface potential at long distances is quadrupolar; at intermediate distances greater than a characteristic atomic dimension it is a screened exponential, with screening length equal to the bulk value. The case of intermediate distance provides a rigorous basis for the exponentially screened surface potential commonly employed to analyze scanning tunneling microscopy images of the depletion or accumulation regions surrounding isolated charges on III-V(110) cleavage surfaces. Certain of these results also apply to colloids. (c) 2000 The American Physical Society.},
doi = {10.1103/PhysRevB.61.13821},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 20,
volume = 61,
place = {United States},
year = {2000},
month = {5}
}