Effects of annealing on the photoluminescence of ZnSe nanorods coated with Au

• Au-functionalized ZnSe nanorods were synthesized.
• The intensity of NBE emission of ZnSe nanorods was enhanced remarkably by Au-coating and H2 annealing.
• The increase in INBE/IDL is due to surface plasmon resonance and hydrogen passivating defects.
• H2 annealing is more efficient in enhancing NBE emission than N2 annealing.

Au-functionalized ZnSe nanorods were synthesized by the thermal evaporation of ZnSe powder followed by Au sputter-deposition and thermal annealing. Photoluminescence (PL) showed that the intensity of near-band edge (NBE) emission of ZnSe nanorods was enhanced remarkably by Au-coating and annealing in a H2 atmosphere. The intensity ratio of NBE emission to the deep level emission, INBE/IDL of Au-coated ZnSe nanorods after annealing in a H2 atmosphere was ∼68 times higher than that of the pristine (unannealed, uncoated) ZnSe nanorods. The increase in INBE/IDL might be due to a combination of carrier transfer from the defect level to the Fermi level of Au nanoparticles, surface plasmon resonance in Au nanoparticles and hydrogen passivated deep level defects.