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Various materials have been investigated at the nanoscale to improve the solar absorber's efficiency in the absorption of solar energy. Here in this paper various structures having multiple layers of thin film combination of Fe2O3 and CuO have been investigated. The thickness of both layers is varying from 500 to 1000 nm with a step size of 100 nm. This structure is numerically investigated with the help of COMSOL multiphysics software in this paper where fabrication of the same can be done by using dip-coating or spin-coating-like methods. The optimized structure provides absorption of about 97% over the solar spectrum. Where average absorption of 98% in ultra-violate and visible regions which cover the high range of solar spectrum and in the infra-red region, an average absorption of 96%. Higher than 95%, 97%, and 99% of absorption in the range of 2340 nm, 1760 nm, and 565 nm are observed, respectively. These materials can also be used in optical detectors from 1405 to 1970 nm range and can be used in optical communication. At the wavelength of 1690 nm, it shows 99.9998% absorption indicating the usefulness of these materials for detection purposes alongside solar-thermal devices. [ABSTRACT FROM AUTHOR]

Since the introduction of Metal-Insulator-Metal (MIM) absorbers, most of the structures demonstrated a narrowband absorption response which is not suitable for potential applications in photovoltaic systems, as it requires higher energy to enhance its performance. Very little research is being conducted in this direction; to address this issue, we exhibit a broadband solar absorber designed using a concentric GST ring resonator placed upon a silicon dioxide substrate layer with chromium used as a ground plane. It was analyzed using the finite element method. The design is also optimized by using a nonlinear parametric optimization algorithm. Comparatively less work has been focused on solar absorbers designed with the help of GST material, and here we have compared the effect of two different phases of GST, i.e., amorphous (aGST) and crystalline (cGST); the results indicate the higher performance of aGST phase. Parametric optimization has been adapted to identify the optimal design to attain high performance at minimal resources. The absorption response is angle insensitive for 0 to 60 degrees, and at the same time for both TE and TM modes, the design provides identical results, indicating the polarization-insensitive properties. The electric field intensity changes at the six peak wavelengths are also demonstrated for the authentication of the high performance. Thus, the proposed concentric GST ring resonator solar absorber can present a higher solar energy absorption rate than other solar structure designs. This design can be applied for improving the performance of photovoltaic systems. [ABSTRACT FROM AUTHOR]

This study aims to design a metamaterial sensor to detect glucose levels in the human body so that the severity of diabetic patients can be determined. The biomolecules are placed over gold metamaterial to observe the behavior of the sensor. The proposed model is analyzed for both phases of GST (amorphous GST [aGST] phase and crystalline GST [cGST] phase). The design is analyzed for parameters like absorption, angle of incidence of light, the concentration of glucose biomolecules, substrate, tuning of the wavelength spectrum, and resonator thickness. The sensor with cGST provides better performance. Observing angle of incidence, 95% absorption is noticed with 48–60° radians for wavelength range 0.85–0.98 μm and with 42–69° radians for wavelength range 0.85–0.98 μm. The analysis depicts that the proposed phase change material‐based biosensor in general and with cGST, in particular, is suitable for glucose detection in the blood of diabetic patients. [ABSTRACT FROM AUTHOR]

We have proposed a graphene-based metasurface solar absorber for broadband visible wavelength range. The absorption analysis for four different designs is represented. We have explored the Four C-shape array metasurface absorber design, Five circle array metasurface absorber design, Five C-shape array metasurface absorber design, and the Four circle array metasurface absorber design for ultraviolet, visible, and infrared regions with the wavelength ranging from 0.2 to 0.8 µm. The highest average absorption is achieved for the four C-shape array metasurface absorber design. Furthermore, the absorptance response is also explored for various parameter variations such as substrate thickness, resonator thickness, and graphene chemical potential. The substrate height and resonator height have a marginal effect on absorptance. We have also analysed the design by placing graphene material spacer between gold layer and SiO2 substrate layer. While the effect of graphene chemical potential on absorptance is negligible for 0.1–0.7 eV, but for graphene chemical potential of 0.9 eV, the absorptance plot shows a sudden decrease at around 0.69 µm wavelength. The proposed metasurface solar absorber can be applied for photovoltaic applications and solar energy harvesting applications. [ABSTRACT FROM AUTHOR]