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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

MID-INFRARED BROADBAND ABSORPTION BASED ON HBN/METAL HETEROSTRUCTURES

Get access (open in a dialog) DOI: 10.1615/IHTC16.mpe.022392
pages 5981-5990

Resumo

Broadband absorbers have received much attention due to a variety of applications, such as photon/thermal-harvesting, detecting and radiative cooling. In this work, we design a mid-infrared broadband absorber by coupling plasmon and phonon polaritons in hBN/metal heterostructures. It can be shown by the dispersion relation contours that hybrid phonon-plasmon polaritons modes can exist in different hBN/metal heterostructures. To meet the condition of exciting these hybrid modes, the shape of hBN/metal heterostructures should be properly designed. Comparing with uniform hBN structure, the absorption band of hBN/metal heterostructure is greatly broadened. In the focused region (6.26 µm < λ < 7.60 µm) the average absorption is high than 96% for the proposed structure. The broadband absorption is dominated by hyperbolic phonon-plasmon polaritons in the Reststrahlen band and surface phonon-plasmon polaritons out of the Reststrahlen band of hBN, respectively. The underlying mechanism of the near-perfect absorption in different regimes is elucidated by power dissipation density distribution. The proposed route will benefit the design of broadband absorbers, especially applied in mid-infrared range.