Improving the electron emission properties of ion-beam-synthesized Ag-Si02 nanocomposites by pulsed laser annealing

In this work, pulsed laser annealing (PLA) was preformed on ion-beam-synthesized Ag-SiO₂ nanocomposites to improve the FE properties of these samples by modifying the size and distribution of the Ag nanoclusters. The PLA was preformed using a 248 nm KrF excimer laser. Multiple pulses, with durations of 25 ns, at an energy density of 250 mJ/cm were accumulated onto the sample. The FE properties of the samples were studied in a high vacuum chamber, with a base pressure better than 5x10^-4 Pa. The current-electric field (I-F) characteristics were measured using a "sphere-to-plane" electrode configuration, with a 5 mm diameter stainless-steel ball anode. The applied electric field was obtained by dividing the applied voltage by the gap distance and the threshold field (F_th) and is defined as the field strength when an emission current of 1 nA is achieved. The microstructure and the surface morphology of these samples are determined by the cross-section transmission electron microscopy (XTEM) and atomic force microscopy (AFM) measurements, respectively.