Luminescence in excess of 1.5 μm at room-temperature of InAs quantum dots capped by a thin InGaAs strain-reducing layer

Abstract

Quantum dots have proved to be of great interest in being useful for the application of the GaAs-based optical devices at the wavelength of 1.3 or 1.55 μm suitable for fiber-optic communication system. We demonstrate 1.52 μm light emission with a narrow linewidth of 22 meV at room temperature from self-assembled InAs quantum dots embedded in an In 0.45Ga 0.55As strain-reducing layer. By capping InAs quantum dots with an InGaAs strain-reducing layer instead of GaAs, the PL peak of InAs quantum dots shifts towards a longer wavelength. We can control the PL peak of InAs quantum dots by changing the indium composition of InGaAs strain-reducing layer. We confirm that InAs quantum dots will also be useful for applications with GaAs-based optical devices that are suitable for fiber-optic communication systems.