SBIR-STTR Award

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.

Keywords:
Gas Diffusion Barriers, Flexible Electronics, Polymer Substrates, Water Vapor Transmission Rate, Atomic Layer Deposition, Molecular Layer Deposition, Multilayers, Roll-To-Roll

ALD NanoSolutions, Inc. is developing flexible gas diffusion barriers to enable FOLEDs, thin film photovoltaics and other devices to be fabricated on polymer substrates in a novel roll-to-roll ALD process. Multilayer barriers films consisting of nanometer thick inorganic and organic layers can be fabricated using atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques. By interspersing the already excellent nanometer thick Al2O3 ALD barrier films with thin, flexible polymeric MLD layers, we can create flexible ultrabarriers. The very low water vapor transmission rates (WVTR) of these ALD/MLD film will be tested using our improved Calcium test. Flexibility of these ALD/MLD multilayer films will be characterized using advanced cracking detection methods and optimized using modeling of the strains in multilayer film stacks. Meeting the aggressive Phase II targets of <1x10-6 g/m2/day WVTR and 5% strain requires a combination of a thorough understanding of the mechanics of a multilayer films, the precise control afforded by ALD/MLD techniques, and advanced testing and characterization methods. Commercialization of these ALD/MLD ultrabarriers will be developed in pilot scale roll-to-roll ALD processing. Using our initial proof-of-concept work, we will build a continuous, multi-cycle, atmospheric ALD deposition head to pioneer ALD on a moving flexible web substrate.

Keywords:
Gas Diffusion Barriers, Flexible Electronics, Calcium Test, Water Vapor Transmission Rate, Atomic Layer Deposition, Molecular Layer Deposition, Multilayers, Roll-To-Roll Proce