Diffusion of water into permeation barrier layers

Abstract

Articles you may be interested inModeling stress development and hydrogen diffusion in plasma enhanced chemical vapor deposition silicon nitride films submitted to thermal cycles Methods of producing plasma enhanced chemical vapor deposition silicon nitride thin films with high compressive and tensile stress Organic light emitting diodes (OLEDs) are attractive candidates for flexible display and lighting panels due to their high contrast ratio. However, the materials in an OLED are oxidized by very small quantities of moisture. Therefore, flexible OLEDs require flexible, thin-film, encapsulation. The authors introduce a set of three techniques for measuring the solubility and diffusion coefficient of water in a permeation barrier layer that is a SiO 2 -silicone hybrid made by plasma enhanced chemical vapor deposition. The techniques are secondary ion mass spectrometry, and measurements of electrical capacitance and of film stress. The measurements were carried out on samples exposed to water or steam at temperatures between 65 and 200 C. From the resulting values of water solubility, diffusion coefficient, and their thermal activation energies, the authors calculate the time one monolayer of water will take to permeate through the bulk of the film. For a 3 lm thick film held at 38 C and 90% relative humidity, the time is 13 years.

Graphene-based nanolaminates as ultra-high permeation barriers

“…While WVTRs and barrier performance can be characterized by a range of techniques 1,4 including MOCON, electrical and optical Ca tests, etc. for each of them sample compatibility and preparation can be a challenge.…”

“…2,3 The maximum allowable permeation rates depend on the required lifetimes for each particular application and hence these rates are constantly under debate. 1,[4][5][6] For example, organic optoelectronic devices generally have the most stringent requirements, and hence are often used as benchmark application for ultra-barrier films.…”

Wearable and Washable Conductors for Active Textiles

“…[36][37][38] Recently, graphene has been used to seal flexible devices. 39 Even though nanometer-thin inorganic coatings can be processed, they are stiff and brittle, making them unsuitable as hermetic seals for stretchable devices.…”

“…Inorganic materials such as silicon dioxides and silicon nitrides have low water permeabilities and have long been used as hermetic seals for electronic devices. − Recently, graphene has been used to seal flexible devices . Even though nanometer-thin inorganic coatings can be processed, they are stiff and brittle, making them unsuitable as hermetic seals for stretchable devices.…”

P‐173: A Novel Method for Evaluating Water Permeability in Sealants by Secondary Ion Mass Spectrometry

“…In addition, by using isotope-labeled water for accelerated testing, it is possible to distinguish water permeating into the materials from previously existing water molecules. In some cases such as SiO x and its related hybrid films, diffusivity of water was successfully evaluated by using D 2 O [2,3]. In the case of organic films, however, diffusion of water in the films is too fast for meaningful diffusion profiles to be obtained toward the depth direction.…”