Fabrication of Low-Density Long-Wavelength InAs Quantum Dots using a Formation-Dissolution-Regrowth Method

Low-density(10～9cm-2),long-wavelength（more than 1300nm at room temperature） InAs/GaAs quantum dots（QDs） with only 1.75-mono-layer（ML） In As deposition were achieved by using a formation-dissolution-regrowth method.Firstly,small high-density In As QDs were formed at 490°C,then the substrate temperature was ramped up to 530℃,and another 0.2ML InAs was added.After this process,the density of the InAs QDs became much lower,and their size became much larger.The full width at half maximum of the photoJuminescence peak of the low density,long-wavelength InAs QDs was as small as 27.5meV.