Proton-irradiation-induced intermixing of InGaAs quantum dots

Abstract

Proton irradiation was used to create interdiffusion in In₀.₅Ga₀.₅Asquantum 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 (5×10¹³–1×10¹⁵ cm⁻²) 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.