Surface-plasmon-mediated emission from metal-capped ZnO thin films

Abstract

The effects of metal coating on the near-band-edge emission of ZnO thin films have been studied by photoluminescence and atomic force microscopy. Large enhancement in emission intensity has been observed from ZnO films when they are capped by Ag while negligible effect is seen on Au-coated films. In addition, the enhancement is found to increase with Ag thickness and the intensity eventually saturates at thickness of 200nm. By introducing MgO as a spacer between the metal coating and ZnO, the enhancement is shown to decrease with increasing the spacer thickness, which suggests the presence of the local fields induced by surface plasmons. As the emission energy of ZnO matches closely with the surface plasmon of Ag, it is speculated that the resonant coupling of the spontaneous emission in ZnO into the surface plasmons enhances the emission efficiency.

Evidence for coupling between exciton emissions and surface plasmon in Ni-coated ZnO nanowires

“…This SP-exciton interaction at the metal/ZnO interface may occur when the SP energy is comparable with the ZnO band gap energy. To evaluate feasibility of the SP formation at the Ni/ZnO interface, we have calculated the SP dispersions for Ni/ZnO and Ni/air interfaces using the known relation [16,17] …”

Light emission and magnetic properties of aluminum films grown on SrTiO3 by molecular beam epitaxy

“…The surfaces of samples are more smooth compared to literature value. 16 The surface height difference are about 7 nm, and average grain size is 25 nm. Experimentally, topographic image ( Figure 5(a)) looks like the magnetic domain topology image ( Figure 5(b)).…”

Anisotropic growth of zinc oxide pillars on silver nanoparticles by oblique angle deposition

“…ZnO is selected because of its tendency of c-axis oriented growth, which presumably contributes to enhance optical anisotropy. In addition, the combination of ZnO with Ag leads to enhanced photoluminescence 9) and photocatalytic effect.…”