Post-growth engineering of InAs/GaAs quantum dots' band-gap using proton implantation and annealing

Proton implantation followed by rapid thermal annealing (RTA) has been employed for the post-growth tuning of the band gap of molecular beam epitaxy grown InAs/GaAs quantum dots (QDs). To enhance QD intermixing, point defects are created by proton implantation at different doses (5 x 1010-1014 cm-2) followed by rapid thermal annealing at 675 deg. C for 30 s. Low-temperature photoluminescence (PL) measurements have shown that the proton-implantation-induced intermixing alters both the optical transition energies and the PL full width at half maximum (FWHM). A purely proton-implantation induced band gap tuning limit of 131 meV has been achieved for an implantation dose of 5 x 1013 cm-2, keeping both the QDs' character and around 46% of the initial integrated PL intensity