Properties of Cold Condensed Silver Chloride and of Cocondensed Silver/Silver Chloride Films. I. UV-VIS-Spectra

Abstract

When vapor of silver chloride is condensed with rates below 1 nm · min -1 onto a substrate at T= 10 K, a non-crystalline film grows. Typical of this film is the absence of the exciton absorption at 240 nm and the presence of a broad absorption extending to wavelengths > 300 nm. When the film is tempered for a few minutes at T > 170 K, it shows the typical UV-VIS-spectrum of crystalline AgCl. When silver is cocondensed with silver chloride, additional absorption around 300 nm can be observed. This situation is stable up to temperatures of T ≦ 200 K. Then silver chloride crystallizes and silver is precipitated, leading to Mie scattering at wavelengths around 500 nm. Concondensation of silver stabilizes the non-crystalline state with respect to deposition temperature and deposition rate. Also the transition temperature non-crystalline/crystalline is increased.