Wideband long wave infrared metamaterial absorbers based on silicon nitride


ÜSTÜN K., Turhan-Sayan G.

JOURNAL OF APPLIED PHYSICS, cilt.120, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 120 Konu: 20
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1063/1.4968014
  • Dergi Adı: JOURNAL OF APPLIED PHYSICS

Özet

In this paper, we present silicon nitride metamaterial absorber designs that accomplish large bandwidth and high absorption in the long wave infrared (LWIR) region. These designs are based on the metal-insulator-metal topology, insulator (silicon nitride), and the top metal (aluminum) layers are optimized to obtain high absorptance values in large bandwidths, for three different silicon nitride based absorber structures. The absorption spectrum of the final design reaches absorptance values above 90% in the wavelength interval between 8.07 mu m and 11.97 mu m, and above 80% in the wavelength interval between 7.9 mu m and 14 mu m, in the case of normal incidence. The difficulty in the design process of such absorbers stems from the highly dispersive behavior of silicon nitride in the LWIR region. On the other hand, silicon nitride is a widely used material in microbolometers, and accomplishing wide band absorption in silicon nitride is crucial in this regard. Therefore, this study will pave the way for more efficient infrared imaging devices, which are crucial for defense and security systems. Additionally, such designs may also find applications in thermal emitters. Published by AIP Publishing.