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• Multi-layer Ni-Al2O3 solar absorber with metal-insulator-metal structure is presented. • Absorbs solar energy from ultraviolet to near-infrared solar radiation band. • Spectral absorption rate approximately 11% higher than traditional photonic crystal. • Beneficial in areas such as solar thermal utilization and thermal photovoltaics. Efficient absorption of solar spectral radiation is a key requirement in solar heat utilization. In an effort to achieve this goal, this study investigated slow light effect and magnetic polaritons, and analyzed other physical model coupling mechanisms in photonic crystals. To construct a class of two-dimensional layers of Ni-Al 2 O 3 as a pyramid array solar energy absorber, the high melting points of Ni and Al 2 O 3 were utilized to create an arrangement of absorbers with good thermal stability, low sensitivity to angle of incidence, and polarization independence. Based on AM1.5 solar spectral data, a simulation study of the photothermal absorption characteristics of this type of absorber in the 0.3–2.5 µm band was conducted. The results showed that the photothermal conversion efficiency is as high as 96.45%. Compared with the traditional single physical effect design, the conversion efficiency of this photonic crystal structure is increased by ~11%. Furthermore, increasing the concentration factor allows the absorber to maintain high efficiency even at high temperatures, which provides theoretical evidence for the efficient use of solar radiation. This work will be beneficial in several areas, including solar thermal utilization, thermal photovoltaics, absorber design, and radiator design in radiant refrigeration systems. [ABSTRACT FROM AUTHOR]

• Multi-layer Ni-Al2O3 solar absorber with metal-insulator-metal structure is presented. • Absorbs solar energy from ultraviolet to near-infrared solar radiation band. • Spectral absorption rate approximately 11% higher than traditional photonic crystal. • Beneficial in areas such as solar thermal utilization and thermal photovoltaics. Efficient absorption of solar spectral radiation is a key requirement in solar heat utilization. In an effort to achieve this goal, this study investigated slow light effect and magnetic polaritons, and analyzed other physical model coupling mechanisms in photonic crystals. To construct a class of two-dimensional layers of Ni-Al 2 O 3 as a pyramid array solar energy absorber, the high melting points of Ni and Al 2 O 3 were utilized to create an arrangement of absorbers with good thermal stability, low sensitivity to angle of incidence, and polarization independence. Based on AM1.5 solar spectral data, a simulation study of the photothermal absorption characteristics of this type of absorber in the 0.3–2.5 µm band was conducted. The results showed that the photothermal conversion efficiency is as high as 96.45%. Compared with the traditional single physical effect design, the conversion efficiency of this photonic crystal structure is increased by ~11%. Furthermore, increasing the concentration factor allows the absorber to maintain high efficiency even at high temperatures, which provides theoretical evidence for the efficient use of solar radiation. This work will be beneficial in several areas, including solar thermal utilization, thermal photovoltaics, absorber design, and radiator design in radiant refrigeration systems. [ABSTRACT FROM AUTHOR]

Solar absorber, which is widely used in concentrated solar thermal systems and solar photovoltaics, has attracted great attention in recent years. Concentrated solar irradiation not only saves production costs, but also effectively improves the photothermal conversion efficiency of the system. However, the huge radiative heat flux will cause the system temperature to rise rapidly, which poses significant challenges for designing solar absorbers. Here, a metasurface absorber based on cylinder array structure is proposed for efficient solar energy harvesting, using the high-temperature resistant materials TiN and SiO 2. The total solar absorption of the absorber is up to 0.94 at wavelengths of 300–2500 nm. The high absorption performance of the metasurface absorber can be explained as the coupling effect of surface plasmon resonance and Fabry-Pérot resonance, which is confirmed by the electric field distribution. Moreover, the effect of geometric parameters on absorption performance is analyzed. Finally, we discuss the influence of incident angle on the solar absorber. We believe this work could deepen the understanding of coupling resonance mode and guide the design of high-temperature solar absorbers. [ABSTRACT FROM AUTHOR]