Growth of high-uniformity InAs∕GaAs quantum dots with ultralow density below 107cm−2 and emission above 1.3μm

Abstract

We report the growth of high-uniformity large coherent InAs∕GaAs quantum dots (QDs) by metal organic chemical vapor deposition, with density between 106 and 1010cm−2, emission close to 1.4μm at room temperature with only GaAs capping, and temperature-independent peak linewidth as low as 14meV. It is shown that the QD density can be controlled by the InAs coverage, while the QD size remains remarkably constant. The observed decrease of the emission wavelength with coverage is explained by a density-dependent alloying. Microphotoluminescence measurement was performed on bare samples at 5K and single dot emission was observed.