Flexible Gas Diffusion Barriers Using ALD/MLD Multilayers and Roll-to-Roll Processing

ALD NanoSolutions, Inc. will develop flexible gas diffusion barriers for polymer substrates that will enable flexible electronic devices such as flexible OLEDs and thin film photovoltaics. The multilayer barriers films will consist of nanometer thick, flexible inorganic and organic layers formed using atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques. Al2O3 ALD films which have previously demonstrated excellent barrier properties will be interspersed with thin, flexible polymeric MLD layers to create flexible ultrabarriers. These ALD/MLD barriers will be fabricated and tested for their water vapor transmission rate (WVTR) using the Calcium test. The flexibility of the ALD/MLD multilayers will be characterized by measuring the critical strain for multilayer film cracking. This novel approach can produce barrier films meeting the Phase I targets of <1x10-3 g/m2/day WVTR and 2% strain. In order to commercialize these ALD/MLD multilayer barriers, the proposed work will also develop roll-to-roll ALD processing. The initial proof-of-concept investigations will characterize prototype atmospheric ALD process equipment to deposit ALD films on a rigid, moving substrate. Subsequent work will expand the capabilities of the process equipment to deposit multiple ALD cycles as a flexible substrate moves past the ALD coating head.