Engineering the Optical and Dielectric Properties of the Ga2S3/In/Ga2S3 Nanosandwiches via Indium Layer Thickness

In this study, the effect of the nanosandwiched indium slab thickness (20–200 nm) on the performance of the Ga2S3/In/Ga2S3 interfaces is explored by means of X-ray diffraction, Raman spectroscopy, and optical spectroscopy techniques. The indium slab thickness which was varied in the range of 20–200 nm is observed to enhance the visible light absorbability of the Ga2S3 by 54.6 times, engineered the energy band gap in the range of 3.7–1.4 eV and increases the dielectric constant without, significantly, altering the structure of the Ga2S3. The broad range of the band gap tunability and the increased absorbability nominate the Ga2S3 thin films for photovoltaic applications. In addition, the dielectric spectral analysis and modeling have shown that a wide variety in the plasmon resonant frequency could be established within the Ga2S3/In/Ga2S3 trilayers. The plasmon frequency engineering in the range of 0.56–2.08 GHz which is associated with drift mobility of 12.58–5.76 cm2/Vs and electron scattering time at femtosecond level are promising for the production of broad band high frequency microwave filters.