Enhancements of Light Absorbability, Optical Conductivity and Terahertz Cutoff Frequency in Stacked Layers of Selenium via Ag Nanoslabs Sandwiching

Abstract

In this work, the effects of insertion of Ag layer of thickness of 100 nm between two stacked layers of selenium are investigated by means of X?ray diffraction, scanning electron microscopy and optical spectrophotometry techniques. While the structural analysis has shown the amorphous nature of growth of the stacked layers of Se, the morphology analysis revealed the formation of nanorods and nanowires that exhibit lengths and diameters in the ranges of 1.5–2.5 ?m and 36–146 nm respectively. The optical spectroscopy analysis has shown that the presence of Ag between stacked layers of selenium enhances the light absorbability, increases the optical conductivity and widens the range of the terahertz cutoff frequency. In addition, Ag layers increased the drift mobility from 15.07 to 35.64 cm2/Vs and extends the plasmon frequency domain of stacked layers of selenium from 0.45–5.60 GHz to 0.62–5.90 GHz. The calculated optical conductivity parameters and the spectral analysis of the terahertz cutoff frequency which varied in the range of 0.35–13.20 THz indicated the applicability of the Ag sandwiched selenium stacked layers as terahertz cavities suitable for visible light communications as band pass filters.