Effect of Morphological Changes due Conductivity Enhancing Post Treatment on the Absorption and Photoluminescence of AgNW Thin Films

The effect of electrical and thermal treatment on silver nanowire (AgNW) network morphology and its impact on ultraviolet-visible (UV/Vis) and luminescence spectra is reported. The results exhibit that the conductivity enhancing welding of the single AgNWs at connection points changes the network morphology towards an increased proportion of spherical like structures. This inhomogeneity which is particularly noticeable for joule heated films not only gives rise to an inhomogeneous line broadening in absorption and luminescence spectra but also causes a red shift of the surface plasmon resonances in comparison to a non post-treated AgNW network. With increasing inhomogeneity either due to welding or beginning degradation the d-sp interband excitation pathway is especially efficient for the decay of surface plasmons and shows the strong coupling of the corresponding exciting and emitting photons to the surface plasmon excitation.