Free Electron Behavior in InN: On the Role of dislocations and Surface Electron Accumulation

Authors

V. Darakchieva, Instituto Tecnológico e Nuclear, 2686-953 Sacavém, Portugal
Tino Hofmann, University of Nebraska - LincolnFollow
Mathias Schubert, University of Nebraska - LincolnFollow
B. E. Sernelius, IFM, Linköping University, SE-581 83 Linköping, Sweden
B. Monemar, IFM, Linköping University, SE-581 83 Linköping, Sweden
P. O. A. Persson, IFM, Linköping University, SE-581 83 Linköping, Sweden
F. Giuliani, IFM, Linköping University, SE-581 83 Linköping, Sweden
E. Alves, Instituto Tecnológico e Nuclear, 2686-953 Sacavém, Portugal
H. Lu, Cornell University, Ithaca, New York
W. J. Schaff, Cornell University, Ithaca, New York

Date of this Version

2009

Comments

Published in APPLIED PHYSICS LETTERS 94, 022109 (2009). Copyright © 2009 American Institute of Physics. Used by permission.

Abstract

The free electron behavior in InN is studied on the basis of decoupled bulk and surface accumulation electron densities in InN films measured by contactless optical Hall effect. It is shown that the variation in the bulk electron density with film thickness does not follow the models of free electrons generated by dislocation-associated nitrogen vacancies. This finding, further supported by transmission electron microscopy results, indicates the existence of a different thickness-dependent doping mechanism. Furthermore, we observe a noticeable dependence of the surface electron density on the bulk density, which can be exploited for tuning the surface charge in future InN based devices.