FREQUENCY-SELECTIVE CHARACTERISTICS OF TWO-DIMENSIONAL RANDOM ARRAY OF FINE SILVER PARTICLES FORMED ON AlN AND TiO2 FILMS

In previous investigations it was shown that a random array of fine silver particles formed on sheet glass works as a frequency-selective screen that reflects near-infrared rays and transmits radio waves. In order to improve the screening efficiency, the use of AlN and TiO2 films with relative dielectric constants of 4.0 and 5.7, respectively, deposited on sheet glass were investigated. For both substrate films resonance reflection occurred at longer wavelengths and the irregular reflectance was lower than for a glass substrate. In particular, the array on the TiO2 film showed a very low value of irregular reflectance and high values of shielding effect and visible light transmittance. These results suggest that a system in which a two-dimensional random array of fine silver particles is fixed on a dielectric film deposited on sheet glass can be applied as a solar control glass, which suppresses near-IR rays and admits radio waves into a room.