Eur. Phys. J. Appl. Phys. 27, 93-95 (2004)
https://doi.org/10.1051/epjap:2004113

Lateral conductivity in GaAs/InAs quantum dot structures

¹ Research Institute for Technical Physics and Materials Science, Konkoly-Thege 29-33, H-1121 Budapest, Hungary
² Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Praha 6, Czech Republic
³ MASPEC Institute - C.N.R., Parco Area delle Scienze 37a, 43010 Fontanini-Parma, Italy

Corresponding author: dozsa@mfa.kfki.hu

Received: 4 July 2003
Accepted: 9 December 2003
Published online: 15 July 2004

Abstract

Lateral conductivity effects have been investigated in self-organised InAs quantum dot (QD) structures grown in a GaAs matrix with different cap layers. Current-voltage (I-V), capacitance-voltage (C-V), DLTS, capacitance and conductance frequency dependence, fast defect transient (FDT), and electron beam induced conductivity (EBIC) measurements were applied. The conductivity in the QD plane decays within a distance of 10 microns. The capacitance transients are dominated by the local QD-plane transversal conductivity and by the free carrier transport in the cap layer. The nonequilibrium free carrier created by electron beam excitation develop a potential barrier at macroscopic distances from the electrical contacts.