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

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2019-10, Vol.216 (20), p.n/a
• Main Authors: Qasrawi, Atef F., Abu Al Rob, Osama H.
• Format: Article
• Language: English
• Subjects: amorphous selenium; Conductivity; Diameters; metal–semiconductor interfaces; Morphology; Nanorods; Nanowires; optical conductivity; Selenium; Spectrophotometry; Spectrum analysis; Structural analysis; terahertz; Terahertz frequencies; Thickness
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201900370

Herein, 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 shows the amorphous nature of growth of the stacked layers of Se, the morphology analysis shows the formation of nanorods and nanowires that exhibit lengths and diameters in the ranges of 1.5–2.5 μm and 36–146 nm, respectively. The optical spectroscopy analysis shows 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 increase the drift mobility from 15.07 to 35.64 cm2 Vs−1 and extend the plasmon frequency domain of stacked layers of selenium from 0.45–5.60 to 0.62–5.90 GHz. The calculated optical conductivity parameters and the spectral analysis of the terahertz cutoff frequency that vary in the range of 0.35–13.20 THz indicate the applicability of the Ag sandwiched selenium stacked layers as terahertz cavities suitable for visible‐light communications as band‐pass filters. Here, the properties of selenium/silver/selenium nanolayers are studied. The amorphous stacked layers are composed of nanowires. The presence of Ag enhances the light absorbability and optical conductivity, widens the range of the terahertz cutoff frequency, increases the mobility, and extends the plasmon frequency domain indicating the applicability of the nanowires as terahertz cavities.