Current commercially available films used to protect these materials have a barrier property or water vapour transmission rate of about 10-3g/m2 per day, or one thousandth of a gram per square meter per day at 25C and 90% relative humidity (RH).
However, the ideal film for organic devices would require a barrier property of better than 10-6g/m2/day at 39C and 90% RH, or one millionth of a gram per square meter per day.
Defects such as pinholes, cracks and grain boundaries are common in thin oxide barrier films when fabricated onto plastic substrates. These defects cause a pore effect, where oxygen and water molecules are able to seep through and penetrate the plastic barrier.
Current barrier technologies focus on reducing these defects by using alternate organic and inorganic multi-layers coated on plastic. These multiple layers stagger corresponding pores in adjacent layers and create a tortuous, lengthy pathway for water and oxygen molecules, making it more difficult to travel through the plastic.
In contrast, IMRE has taken an innovative approach to resolve the pore effect by literally plugging the defects in the barrier oxide films using nanoparticles. This reduces the number of barrier layers needed in the construction of the barrier film down to two layers in this unique nanoengineered barrier stack. IMREs barrier stack consists of barrier oxide layers and nanoparticulate sealing layers.
The nanoparticles used in the barrier film have a dual function - not only sealing the defects but also actively reacting with and retaining moisture and oxygen.
The result is a breakthrough moisture barrier performance of better than 10-6g/m2/day, or one millionth of a gram per square meter per day, which surpasses the requirements for flexible organic device substrates.
The barrier f
|Contact: Cathy Yarbrough|
Agency for Science, Technology and Research (A*STAR), Singapore