Infrared blocking, microwave and terahertz low-loss transmission AlN films grown on flexible polymeric substrates

Abstract

Aluminum nitride (AlN) film coatings on flexible substrates (polymeric Teflon, Mylar) have been obtained using a hybrid helicon-arc ion-plasma deposition technique with high adhesion of coatings. Studies of optical, morphological, and structural properties of AlN films have been carried out. It was found that AlN coatings on Teflon and Mylar thin-film substrates substantially suppress transmission of infrared (IR) radiation within the spectral range λ ∼ 5–20 μm at certain technological parameters and thickness of AlN. Transmission in THz regions by using quasioptics attains T ≈ 79%–95%, and losses measured in the channels within the microwave region 2 to 36 GHz are <0.06 dB. The obtained composite structures (AlN coatings on Teflon and Mylar thin-film substrates), due to a high thermal conductivity of AlN, could be used as efficient blocking structures in the infrared spectral range (“infrared stealth”) withdrawing the heat from filters warmed by IR radiation. At the same time, they can be used as the transparent ones in the microwave and THz regions, which can be important for low-temperature detector components of navigation, positioning, and telecommunication systems due to reducing the background noise.

Synthesis, Characterization, and Infrared Blocking Efficiency of Polyvinyl Alcohol Composites Filled with Cadmium Sulfide and Zinc Sulfide NPs

“…With increasing absorbance, the transmittance decreases, albeit slightly according to the law of conservation of energy. this is since the agglomeration of NPs with increasing content and increase of the number of charge carriers These are consistent with the results of researchers [21,25].…”

Electronic Structure of Aluminium Nitride and Its Solid Solutions with Oxygen and Aluminium

“…This is also consistent with the fracture toughness exhibited by AlN, which might be attributed to its partially covalent nature [13]. Spectroscopic investigations of AlN include techniques such as combination scattering and infrared spectra [14][15][16]23], reflection and transmission spectra [24], x-ray emission spectra [25]. Ultraviolet photoemission spectroscopy (UPS), electron energy loss spectroscopy (EELS), and Auger spectra have been reported [26,27].…”

Infrared blocking materials

“…The IR blocking filters based on AlN nanostructured thin films deposited on different polymeric substrates, particularly on the Teflon and Mylar films, by the low-temperature ion-plasma technique, are investigated. Due to the location of the residual band of AlN (Restrahlend band, almost 100 % reflection [2]), nanostructured surface morphology peculiari- , and ordinary gray oil paint (c) on the top of a hot plate heated to the temperature T = 64.9 °С (1) and distribution of the effective temperature along line "1" (2) obtained with a Mikron M7800 IR camera ties, and the high thermal conductivity (γ ≈ 134÷180 W/m ⋅ K), such thin films composite structures effectively block an IR radiation from the wavelengths 10.3 microns up to almost 20 microns [3]. Fig.…”