Electroluminescent Textiles using Sputter-deposited Amorphous Nitride-Rare-Earth Ion Coatings

Wide bandgap semiconductors have been sputter deposited onto non-crystalline substrates, low melting point materials, including polymer fibers, textiles and glasses. The semiconductors are amorphous and can be deposited over large (square meter) areas economically. The electro-optical properties of these materials are not defect limited, and do not require thermal processing. Alternating current electroluminescent device structures/coatings composed of rare-earth ion doped nitrides have been deposited onto point-bonded fabrics, polymer membranes, and polymer sheets. Light emission is detected from the coated fabrics over the entire visible range, UV and IR. A notable feature of fabric-based structures is the inclusion of ambient air in the fabric voids. Increased light emission intensity is obtained by extracting electrons from the plasma discharge during device operation. These fabrics do not require weaving, which could be difficult with semi-crystalline or brittle semiconductor materials. Multilayer assembly and bonding with continuous sheets, cladding, filling and or contact bonding are all available at any point in the fabric assembly. Non-woven, pin-bonded, materials may still function after some damage, e.g. rips or punctures, due to redundant connections at each pad. Further advantages are the simple incorporation of optically active ions, such as rare earths, high thermal conductivity, high breakdown voltage, and complete miscibility of the group III-A and -B nitrides, allowing bandgap engineering. The deposition process is scalable and may be applied to the fibers or yarns before or after fabric formation.