Over 1.5 μm light emission from InAs quantum dots embedded in InGaAs strain-reducing layer grown by metalorganic chemical vapor deposition

We demonstrated the 1.52 μm light emission at room temperature from self-assembled InAs quantum dots embedded in the ${\mathrm{In}}_{\mathrm{0.45}}{\mathrm{Ga}}_{\mathrm{0.55}}\mathrm{As}$ strain-reducing layer. By capping InAs quantum dots with an InGaAs strain-reducing layer instead of GaAs, the photoluminescence peak of InAs quantum dots can be controlled by changing the indium composition of the InGaAs strain-reducing layer. The full width at half maximum is as narrow as 22 meV. The wavelength of 1.52 μm is the longest wavelength so far achieved in self-assembled InAs quantum dots, which would be promising to quantum-dot lasers on GaAs substrate for application to light sources in long-wavelength optical communication systems.