Microstiructure and electronic characterization of InGaAs containing layers of self-assembled ErAs nanoparticles

We report the growth by molecular-beam epitaxy of a composite epitaxial material consisting, of layers of semimetallic ErAs particles embedded in an In0.53Ga0.47As matrix. The ErAs particles were found to be 14 +/- 3 Angstrom high (similar to4 monolayers) and varied in area depending on amount of ErAs deposited. The material was found to be strongly n-type for depositions less than one-half of a monolayer. As the deposition of ErAs increases. the lateral size and density of I the panicles also increases, resulting in a more rapid freeze out of the electrons and reduction of the free electron concentration at 300 K. We find the free electron concentration can be further reduced by compensation with beryllium, leading to more resistive material. (C) 2002 Elsevier Science B.V. All rights reserved.