Proton implantation-induced intermixing of InAs/ InP quantum dots

Proton implantation-induced intermixing of InAs quantum dots QDs capped with InP, GaInAsP, and InP and InGaAs layers grown by metal-organic chemical vapor deposition is investigated. The samples are annealed at 750, 800, 850, and 900 °C for 30 s and thermal stability of the QDs is studied. The optimum annealing temperature is around 800 °C which gives maximum implantation-induced energy shift. The QDs capped with InP layers show the highest implantation-induced energy shift due to strong group V interdiffusion whereas the QDs grown on and capped with GaInAsP layers show the least implantation-induced energy shift due to weak group V and group III interdiffusion. The QDs capped with InP and InGaAs layers show intermediate implantation-induced energy shift and are less thermally stable compared to the QDs grown on and capped with GaInAsP layers. The QDs capped with InP layers show enhanced photoluminescence PL intensity when implanted with lower proton dose less than 5 1014 ions/cm2 . On the other hand higher proton dose more than 1 1014 ions/cm2 reduces the PL linewidth in all samples. © 2006 American Institute of Physics. DOI: 10.1063/1.2208371