Growth of low density InGaAs quantum dots for single photon sources by metal-organic chemical vapour deposition

We report the preparation of low density self-assembled InGaAs on GaAs grown by metal-organic chemical vapour deposition for single photon sources. Through using a set of optimized growth parameters, including the arsine partial pressure, total coverage of quantum dots, and growth temperature, high optical quality quantum dots with density as low as 5 x 10(6) cm(-2) have been obtained. Using local optical excitation through a sub-micron aperture of a single quantum dot, its spectral lines associated with the exciton, biexciton, multi-exciton, and charged exciton have been resolved and identified. Photon correlation measurements show that the single quantum dot can successfully emit antibunched photons.