Structure- and excitation-dependent photoluminescence of As-S:Yb3+ films

In the article, we present and discuss the features of the structure and photoluminescence properties of Yb-doped As-S films synthesized by PECVD employing solid-state initial precursors. The doping was carried out during the deposition process. By controlling the temperature of the precursor sources and the composition of the lowtemperature nonequilibrium plasma, we synthesized amorphous As-S:Yb films with Yb content ranging from 0.6 to 8.4 at. %. The change in the ratio of structural elements and surface morphology as a function of the elemental composition is shown. The increase of the Yb content leads to a redshift of the short-wavelength absorption edge. The dependence of the shape and intensity of 2F5/2 -> 2F7/2 photoluminescence, observed in the range 930-1030 nm on the excitation wavelength (632.8 nm and 785 nm) and Yb concentration was evaluated. The relation between composition and atomic structure of the amorphous matrix of arsenic sulfide on the photoluminescent properties of Yb3+ ions is discussed.