Infrared absorption of thin metal films: Pt on Si

Abstract

It is shown that metal films will absorb more infrared radiation if they are made thinner. For most metals, the maximum absorptance is obtained for films which are less than 100 Å in thickness. Experiments are reported here for Pt on Si, for which peak absorptance of 3.39-μm radiation incident through the Si is found to be 0.5±0.1 for a film 80 Å thick.