Proton implantation-induced intermixing of InAs/InP quantum dots

摘要

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℃ for 30 s and thermal stability of the QDs is studied. The optimum annealing temperature is around 800 ℃ 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 X 10~(14) ions/cm~2). On the other hand higher proton dose (more than 1 X 10~(14) ions/cm~2) reduces the PL linewidth in all samples.