Silver nanocrystals with the average diameter down to 4 nm were synthesized in Al2O3 matrix on Si substrate by pulse laser deposition followed by annealing at 400 degrees C in N-2 ambient. A photo luminescence (PL) band centered at 2.27 eV was recorded. A model based on the PL spectrum induced by the radiative recombination of sp-band electrons with d-band holes in the silver nanocrystals is suggested. Metal-insulator-semiconductor structures with Silver nanocrystals embedded in Al2O3 gate dielectric were fabricated. Large hysteresis behaviour in terms of large memory window and good data retention were characterized by capacitance-voltage and capacitance-time measurements. (c) 2008 Elsevier B.V. All rights reserved.