Open Access Nano Express

Study of the vertical transport in p-doped superlattices based on group III-V semiconductors

Osmar FP dos Santos1, Sara CP Rodrigues1*, Guilherme M Sipahi2, Luísa MR Scolfaro3 and Eronides F da Silva Jr4

Author Affiliations

1 Departamento de Física, Universidade Federal Rural de Pernambuco, R. Dom Manoel de Medeiros s/n, 52171-900 Recife, PE, Brazil

2 Instituto de Física de São Carlos, USP, CP 369, 13560-970, São Carlos, SP, Brazil

3 Department of Physics, Texas State University, 78666 San Marcos, TX, USA

4 Departamento de Física, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901, Recife, PE, Brazil

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Nanoscale Research Letters 2011, 6:175  doi:10.1186/1556-276X-6-175

Published: 25 February 2011

Abstract

The electrical conductivity σ has been calculated for p-doped GaAs/Al0.3Ga0.7As and cubic GaN/Al0.3Ga0.7N thin superlattices (SLs). The calculations are done within a self-consistent approach to the <a onClick="popup('http://www.nanoscalereslett.com/content/6/1/175/mathml/M1','MathML',630,470);return false;" target="_blank" href="http://www.nanoscalereslett.com/content/6/1/175/mathml/M1">View MathML</a> theory by means of a full six-band Luttinger-Kohn Hamiltonian, together with the Poisson equation in a plane wave representation, including exchange correlation effects within the local density approximation. It was also assumed that transport in the SL occurs through extended minibands states for each carrier, and the conductivity is calculated at zero temperature and in low-field ohmic limits by the quasi-chemical Boltzmann kinetic equation. It was shown that the particular minibands structure of the p-doped SLs leads to a plateau-like behavior in the conductivity as a function of the donor concentration and/or the Fermi level energy. In addition, it is shown that the Coulomb and exchange-correlation effects play an important role in these systems, since they determine the bending potential.