GaInP 2 overgrowth and passivation of colloidal InP nanocrystals using metalorganic chemical vapor deposition

Abstract
We have used metalorganic chemical vapor deposition to deposit thin GaInP2 passivating films on both isolated and close-packed arrays of colloidal InP/GaInP2 core-shell nanocrystals. Conformal GaInP2 layers of 10–20 nm were grown on the nanocrystals after organic capping molecule removal by a thermal annealing treatment. We show that the InP nanocrystals retain their crystallinity, shape and luminescence efficiency after being exposed to growth temperatures of 600 °C. The GaInP2 nanocrystal composite showed strong photoluminescences indicating effective passivation of surface states. In close-packed nanocrystal arrays, the emission band is redshifted compared to films of isolated nanocrystals indicating electron coupling between dots embedded in GaInP2.