GRAVIA - Contiguous graphene ultra-barrier films for flexible electronic applications

Lead Research Organisation: University of Cambridge
Department Name: Engineering

Abstract

The project will investigate the feasbility of producing very high quality barrier films in MOCON test formats for next
generation flexible OLED and plastic logic display applications.These exhibit ultra low water vapour transfer rates (WVTR)
of less than 1 X 10-5 g/m2 per day using self healing layers of high quality CVD graphene and Atomic Layer Deposited
(ALD) amorphous alumina. The work will explore the neccessary industrial process parameters to ensure the lowest price
point at which the minimum barrier properties can be delivered for the chosen high end application. These resultant
polymer supported barrier films will then be benchmarked against existing barrier coatings in WVTR and mechanical flex
tests. These measurements will also be made traceable by the National Physical Laboratory (NPL) to ensure that the data
claims are correct and meaningful comparisons can be made. The industrial innovation challenge will be producing this
fully flexible, self-healed (contiguous), optically transparent film of 25cm2 (beyond the current state of art 4cm2) in a timely
manner with very few acceptable defects to ensure ultra-barrier performance. The project will utilise advanced
characterisation metrologies and quality control analysis to ensure the iterative development of the films and the resultant
understanding gained from the feasibility studies will be used to model and anticipate future larger film systems and will
also be exploitated where possible by barrier seeking end users and through joint KTN activities to target these
communities.

Planned Impact

The project addresses key questions pertinent to industrial materials development for graphene. The project focus is on a
highly promising near term application for graphene, namely barrier layers, but the developed CVD, ALD and polymer
process technology are highly relevant to a whole application horizon of graphene. Our project targets to mature graphene
technology and our project not only presents an excellent business case but at the same time links ongoing EPSRC and
ERC/EU funded graphene research to the developing Graphene Applications Innovation Centre as part of the HVM
catapult led by the CPI and supported by TSB, and brings together a complete value chain of industrial partners. This is
highly relevant to the academic graphene research and is crucial in helping UK businesses accelerate the
commercialisation of new and innovative technologies. We infer that the technology created will yield long-term economic
benefits to the UK, which will accrue as capability grows.
The immediate route to impact of the research is through Plastic Logic via testing by CPI and NPL. Plastic Logic has
brought substantial investment into the UK by attracting a number of international investors. They will take test structures
developed by the project and look at how feasible it is to apply them to their own post processing to fabricate electronic
devices (OLED's and transistor stacks).
The commercial impact of the research is that the industrial end user partner Plastic Logic are targeting the test barrier
films at the tablet and smartphone display segment as the area that aligns with its value generation. IDC (2013) forecasts
shipments for both smartphone and tablet units to reach 1866M by 2017 of which 14.4M are going to have flexible displays
(IHS report 2013). By 2020, flexible display shipments for both smartphone and tablet applications are expected to rise to
93.1M. Plastic Logic is developing manufacturing supply models to address this range of volume opportunities which
include partnering, technology licensing and transfer. It is recognised though that for these types of business models not all
the potential value will accrue to Plastic Logic. Display pricing will be in the mid to low $20s with larger scope for royalties
(~5%) as %margins will be richer and the display will be a higher % element of value. This end market opportunity together
gives conservative projections for potential sales for Plastic Logic of $10M in 2017 rising to $40M in 2020.
The longer term societal impact of our project can be significant in particular through the diverse set of applications that
graphene offers and that promise for instance new form factors in life style electronics and displays, mass sensing
applications in healthcare, security and environmental protection, environmentally friendly solutions for general lighting,
improved military imaging and fire safety.

Publications

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Description Permeation barrier films are critical to a wide range of applications, and in particular for organic electronics and photovoltaics not only ultra-low permeation values are required but also flexibility, and tuning of properties like optical transparency and conductivity. A laminate structure thereby allows synergistic effects between different materials. We developed combination of chemical vapour deposition (CVD) and atomic layer deposition (ALD) to create in scalable fashion nanolaminates of few-layer graphene and aluminium oxide. The resulting sub-10 nm contiguous, flexible graphene-based films are 95% optically transparent and show water vapour transmission rates below 7×10-3 g/m2/day measured over areas of 5×5 cm2. We deploy these films to provide effective encapsulation for organic light-emitting diodes (OLEDs) with measured half-life times of >900 h in ambient.
Exploitation Route The findings will be published in high impact international journal, and knowledge will be transferred to ongoing related projects.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

 
Description This project is a feasibility study on producing graphene-based barrier films for next generation flexible OLED lighting and display products. Current commercially available barrier layers used to protect the electronics in display screens have limitations with regards to flexibility. In order to realise the commercialisation of such applications, display manufacturers have to be able to source flexible barrier platforms such as graphene on which they can fabricate their displays. The project looks at the incorporation of graphene interlayers which offers great potential for flexible displays. Its gas blocking properties will enable barrier materials that are not only flexible, but also transparent, robust, and very impervious to many molecules. The project will seek to accelerate product development, improving upon current ultra barrier performance and lifetimes by producing consistent barrier materials and processes on large area substrates by utilising specialist growth techniques. A first prototype graphene-based membrane has been demonstrated showing ultra-low permeation values comparable to commercial barrier as well as flexibility, conductivity and transparency that current commercial films cant offer.
First Year Of Impact 2015
Sector Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Construction,Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology
Impact Types Societal,Economic