Ultrahigh barrier coating deposition on polycarbonate substrates

Abstract

The use of polycarbonate film substrates enables fabrication of applications, such as flexible display devices, lighting devices, and other flexible electro-optical devices, using low cost, roll-to-roll fabrication technologies. One of the limitations of bare polycarbonate material in these applications is that oxygen and moisture rapidly diffuse through the material and subsequently degrade the electro-optical devices. This article summarizes recent results obtained at GE Global Research to solve the oxygen and moisture diffusion issue. It will be shown that through the application of thin, dense, plasma-based inorganic coatings one can significantly reduce the oxygen and moisture permeation rate through polycarbonate films. However, as a result of defects that are commonly present in these inorganic coatings there is a limit to the performance of such barrier coatings. To further improve the barrier performance, advanced barrier coatings comprising both inorganic and organic materials have been developed. Both modeling and experimental results will be presented that explain why these hybrid material barrier coatings are capable of reaching ultrahigh barrier performance.

Using hot wire and initiated chemical vapor deposition for gas barrier thin film encapsulation

“…However, contrary to that of glass substrates, the permeability for oxygen and moisture of these materials is high. Since sensitive electronic devices can easily be damaged by oxidation of their active layers, the application of flexible substrates for such devices is hampered by challenges in applying moisture barrier encapsulation [1,2]. In Fig.…”

The role of carrier gas flow in roll-to-roll AP-PECVD synthesized silica moisture barrier films

“…The tailored surface can be either highly hydrophilic and possess adhesive properties with specific chemical reactive sites, or can be repellent to liquids with hydrophobic or oleophobic properties [13,14]. In addition, the vertical variation in the film properties can be exploited in anti-reflection coatings [15] by creating a gradient in the refractive index, in membrane layers by producing a gradient in the size and inter-connectivity of the porosity or in films with a gradient in the chemical composition for the synthesis of ultra-low moisture barrier films [6,16,17]. In other applications the vertical gradient properties can be highly undesirable, for example, in silicon microstructures used for electronic devices demanding uniform electrical properties [3].…”

Supertough UV-curable silane/silica gas barrier coatings on polymers

“…Considerable effort is ongoing to develop super high barrier coatings to protect emerging flexible electronic devices from environmental degradation. These coatings are based on a variety of oxide and nitride multi-layers, leading to barrier improvement factors over uncoated polymer as high as 10 6 (e.g. [6][7][8][9][10]).…”

“…These coatings are based on a variety of oxide and nitride multi-layers, leading to barrier improvement factors over uncoated polymer as high as 10 6 (e.g. [6][7][8][9][10]). In spite of such an outstanding barrier performance, the inorganic coatings remain brittle, with a critical strain for cracking usually in the range from 0.5% to 2% [4].…”