Multi-resonant refractory prismoid for full-spectrum solar energy perfect absorbers

In this work, a feasible way for perfect absorption in the whole solar radiance range is numerically demonstrated via the multiple resonances in a 600-nm-thick refractory prismoid. Under the standard AM 1.5 illumination, the measured solar energy absorption efficiency reaches 99.66% in the wavelength range from 280 nm to 4000 nm, which indicates only a rather small part of solar light (0.34%) escaped. The record harvesting efficiency directly results from the near-unity absorption for the multi-layer refractory resonators, which can simultaneously benefit from the multi-resonant behaviors of the structure and the broadband resonant modes by the material intrinsic features. The absorption including the intensity and frequency range can be adjusted via the structural features. These findings can hold wide applications in solar energy related optoelectronics such as the thermal-photovoltaics, photo-thermal technology, semiconductor assisted photo-detection, ideal thermal emitters, etc.