Microstructure 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 View the MathML source high (∼4 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 the particles also increases, resulting in a more rapid freeze out of the electrons and reduction of the free electron concentration at View the MathML source. We find the free electron concentration can be further reduced by compensation with beryllium, leading to more resistive material.