abstract

• Plasmonic near-perfect absorbers, comprising metal films with a periodic array of subwavelength openings, were deposited on the surface of pyroelectric materials to create wavelength-selective far-infrared detectors. The detectors fabricated and investigated were based on one of two pyroelectric materials: (i) z-cut monocrystalline lithium tantalate (LiTaO3) wafers or, (ii) reactively sputtered aluminum nitride (AlN), with absorbers fabricated by contact photolithography. Spectrally selective absorption resonances were demonstrated by Fourier-transform spectroscopy. Spectrally-selective photoresponse was demonstrated with a tunable THz backward wave oscillator. Responsivity was estimated using a black body source to be ∼1 mV/W for AlN samples and ∼100 mV/W for LiTaO3 samples. Most similar work has focused on detectors for mid-wave and long-wave infrared spectral regions. Our focus on THz wavelengths beyond 20 μm is motivated by specific security and contraband sensing applications. Copyright © Materials Research Society 2020.

authors

• Arose C.
• Cetnar J.
• González Contreras Francisco Javier
• Loparo Z.
• Peale R.E.
• Terracciano A.C.
• Vasu S.S.

publication date

• 2020-01-01

published in

• MRS Advances  Journal

keywords

• Aluminum nitride; Films; III-V semiconductors; Infrared radiation; Lithium tantalate; Microwave oscillators; Tantalum compounds; Terahertz waves; Tungsten compounds; Aluminum nitride (AlN); Backward wave oscillator; Far-infrared detector; Fourier transform spectroscopy; Metal surface structure; Pyro-electric detectors; Pyroelectric materials; Wavelength-selective; Nitrogen compounds

Digital Object Identifier (DOI)

• 10.1557/adv.2020.291

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