Influence of annealing on optical, morphological and electrophysical properties of granular silver nanostructures

The optical, morphological and electrophysical properties of silver nanostructures fabricated by electron beam evaporation and annealed at temperatures of 145 and 195 °C were studied. All samples are characterized by the presence of a pronounced surface plasmon absorption resonance band in the visible range and represent close-packed monolayers of nanoparticles, the average sizes of which increase from ~10 nm in the original samples to ~35–40 nm and ~45–60 nm in the annealed ones, depending on the annealing temperature. The influence of various factors on the spectral characteristics of samples, including the size of nanoparticles and electrodynamic interactions between nanoparticles, is discussed. It has been shown that all granular nanostructures studied, both initial and annealed, are highly resistive. It has been established that for the initial and annealed at 145 °C samples, near low values of the applied voltage, a dependence of the current on the irradiation wavelength can be traced, with its value changing up to two orders of magnitude for certain wavelengths.