Proton-irradiation-induced intermixing of InGaAs quantum dots

Proton irradiation was used to create interdiffusion in In0.5Ga0.5As quantum dots ~QDs!, grown by low-pressure metalorganic chemical vapor deposition. After 25-keV proton irradiation, the QD samples were annealed at two temperatures ~700 or 750 °C! for 30 s. It was found that much lower annealing temperatures were needed to recover the photoluminescence signals than in the quantum-well case. Large blueshifts ~120 meV! and narrowing of the photoluminescence spectra were seen. Various doses (5310– 1310 cm) and implant temperatures ~20–200 °C! were used to study the interdiffusion processes in these samples. In QD samples, much lower doses were required to achieve similar energy shifts than reported in quantum-well samples. © 2003 American Institute of Physics. @DOI: 10.1063/1.1561153#