GaInP_(2) overgrowth and passivation of colloidal InP nanocrystals using metalorganic chemical vapor deposition

摘要

We have used metalorganic chemical vapor deposition to deposit thin GaInP_(2) passivating films on both isolated and close-packed arrays of colloidal InP/GaInP_(2) core-shell nanocrystals. Conformal GaInP_(2) 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℃. The GaInP_(2) 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 GaInP_(2).