The gas barrier properties of ethylene vinyl alcohol copolymer (EVOH) against oxygen, carbon dioxide and water vapor have been widely investigated in relation to different material characteristics, environmental conditions and new processing technologies. Recently, EVOH is gaining more attention as a barrier material against other gases and organic substances such as aromas, flavors, fuels, chemicals (e.g., BTEX), and as a functional barrier, e.g., to avoid mineral oil migration. This review contains an update on permeability data of EVOH emphasizing its potential as a barrier material for new and versatile applications in food and pharmaceutical packaging, agriculture, construction, automotive, etc.

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We report on the first InAs0.85Sb0.15 infrared photodiodes, grown on GaAs and GaAs-coated Si substrates by molecular beam epitaxy. Transmission electron microscopy images reveal a good structural quality. The electrical characteristics of the photodiodes were analyzed using current-voltage, current-temperature, and capacitance-voltage measurements. The spectral response and detector noise were measured at 77 K, resulting in a peak detectivity at 3.8 μm of 1.5×1011 cm Hz1/2/W for InAs0.85Sb0.15/GaAs and 5.0×1010 cm Hz1/2/W for InAs0.85Sb0.15/GaAs/Si.

InAs p-n diodes have been grown on GaAs and GaAs-coated Si substrates by molecular beam epitaxy. Transmission electron microscopy cross sections of the epilayers demonstrate a good structural quality. Photodiodes were obtained using a Be (p=5×1016 cm−3) and Si (n=3×1016 cm−3) doping scheme. The diodes exhibited 77 K zero-bias resistance area products of 2200 Ω cm2 for InAs/GaAs and 1500 Ω cm2 for InAs/GaAs/Si. The spectral response of the devices peaked at 2.95 μm with Johnson noise limited detectivities D* of 7.0×1011 cm Hz1/2/W for InAs/GaAs and 5.8×1011 cm Hz1/2/W for InAs/GaAs/Si. These results clearly demonstrate the feasibility of the monolithic integration of InAs infrared detectors and GaAs or Si read-out electronics.