Effect of GaNAs strain compensating layer over InAs quantum dots grown by MOMBE

We demonstrated the 1.55 μm light emission at room temperature from self-assembled InAs quantum dots embedded inside the GaNAs strain-compensating layer. InAs quantum dots have been capped with tensile strained GaNAs instead of InGaAs and GaAs to compensate the compressive strain formed due to InAs QDs to keep the total strain of the system minimum; as a result the PL peak of InAs QDs shifts towards longer wavelength depending on the N% in GaNAs. The wavelength of 1.55 μm is the longest wavelength so far achieved in self-assembled quantum dots grown on GaAs substrates, which would be promising for application to light source in long-wavelength optical-fiber communication system.