Limits and Properties of Size Quantization Effects in InAs Self Assembled Quantum Dots

Abstract

AbstractIn this paper we report on the limits and properties of size quantization effects in InAs self assembled quantum dots (QDs). Size, density and character of the InAs islands are investigated by transmission electron microscopy. The electronic and optical properties of the islands in the coherent and dislocated growth regime are studied using capacitance, photoluminescence, photovoltage and photocurrent spectroscopy. In the data measured with the different techniques, the change in dot size and density as well as the transition from coherent to dislocated island growth is clearly observable. An increasing QD size causes a red shift in the energetic position of the QD features while the density of the islands is reflected in the intensity of the QD signal. The decrease in intensity at high InAs coverage is attributed to dislocated island formation.