Nanostructured metal-ZnO systems provide an ideal workbench for studying the dynamics of exciton-plasmon coupling.
In order to characterize the interactions, we grew tri-layer structures comprising thin films of ZnO, variable-thickness
spacer layers of MgO, and thin films of Ag or Au. Analysis of the photoluminescence of these structures as a function
of increasing MgO thickness confirms the existence of surface plasmon polariton-exciton coupling through Purcell
enhancement of the excitonic emission for MgO films thinner than 30 nm, and through emission at the SPP resonance
for MgO films thicker than 30 nm. Further, we demonstrate the enhancement of the ZnO impurity photoluminescence
through dipole-dipole scattering with Ag and Au LSPs. Preliminary degenerate band-edge pump-probe measurements
confirm the conclusions developed from photoluminescence measurements. In order to disentangle and further quantify
the interactions seen in these systems, we are lithographically patterning metal nanoparticle arrays and metal hole arrays
on ZnO quantum wells and beginning to perform white-light pump-probe spectroscopy to fully characterize the
dynamics of energy transfer within these systems.
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