The influence of surface grown Ag particle on the optical absorption of Ag/SiO2 nanocomposite film

The Ag/SiO2 composite thin film was prepared by r.f. magnetron co-sputtering. The film samples were investigated using transmission electron microscopy and atomic force microscopy, which show particle size distribution is almost the same for different deposition time, but shorter deposition time and lower sputtering power cause more surface grown Ag particles. Optical absorption was measured for different samples. Theoretic calculation was made based on particle/matrix dipole interaction. The calculation and experiment both show that the higher particle density on film surface cause optical absorption spectrum shift to higher wavelength. (C) 1997 Elsevier Science Ltd.