Blue single photon emission from a single InGaN/GaN quantum dot in nanowire up to 200K

Short wavelength single photon sources are useful for quantum optical devices, in particular for applications such as free space quantum cryptography. Semiconductor quantum dots (QDs) have proven to be ideal for the generation of single photons and single photon sources have been demonstrated with InAs, InP, ZnSe and GaN quantum dots at temperatures ranging from 4K to 300K.^1-4 GaN nanowires with InGaN disks inserted in them have been successfully grown on (001) and (111) Si by us and other groups.^5-7 By shrinking the diameter of these nanowires to 15-20nm, the disks electronically behave like quantum dots. The optical emission from the InGaN dots can be varied over a wide range of the visible spectrum by varying the In composition. We report here, single photon emission at λ=403nm (blue) from a single InGaN dot in a GaN nanowire at 200K.