Metamaterial Solar Absorber Based on TiN/TiO2 Multilayer Taper Structure

The increasing demand for renewable energy has increased in the last decade due to climate change resulting from conventional energy and solar cells become popular. The perfect absorption in solar cells can be achieved with artificially engineered materials at low cost for solar absorbers with high efficiency. A perfect ultra-broadband solar absorber can be achieved by using metamaterial (MM) based on surface plasmon resonance phenomena. We design a near-ideal ultra-broadband plasmonic MM absorber for solar energy harvesting over an ultra-broadband wavelength range (0.4-4 mu m). The structure is made up of periodic taper arrays consisting of a thin, multilayered titanium nitride-titanium dioxide MM. The proposed structure has an absorption greater than 96% between the visible to infrared (IR) regime. It is independent of both polarization and incident angle. The large operational bandwidth, high absorption percentage, and compact thin structure combined with the strong thermal stability of metal TiN make an advantageous choice for solar thermophotovoltaics.