In-Situ Observation of Photodoping Process by Infrared Attenuated Total Reflection Method

Attenuated total reflection (ATR) spectra of a Ag/As2S3 double layer deposited on a Ge prism were observed. Three samples having the As2S3 layer thicknesses of 750 A, 3000 A and 12000 A were studied. Characteristic spectra related to As2S3 thickness, light-irradiation time and wave number were obtained. The spectra were fitted by a simulation procedure using a multilayer model. The spectra were well fitted by introducing the interface layer of a Ag cluster having the thickness typically of 1 nm at the diffusion front of the photodoped region. Spectra and fitted results were discussed in relation to the photodoping mechanism.