Overview
ABSTRACT
Environmental barrier coatings are thin films or multilayer structures that limit mass transfer between a material and its environment, reducing gas penetration (water vapor, oxygen, CO₂) or preventing loss of volatile compounds. They are critical for product performance, durability, and reliability in applications ranging from food packaging to advanced electronics. Atomic Layer Deposition (ALD) is a key technology for such coatings, enabling highly uniform, conformal, and dense films with precise nanometer-scale thickness control through self-limiting surface reactions. These ALD layers provide strong barrier properties even at very low thicknesses and can be deposited at low temperature on sensitive substrates. Applications include microelectronics, OLEDs, photovoltaics, and packaging. The article reviews gas permeation principles, characterization methods, ALD encapsulation materials and mechanisms, and links process parameters to barrier performance and industrial applications.
Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.
Read the articleAUTHORS
-
Frédéric MERCIER : CNRS Research Fellow, - Laboratory of Materials and Processes Science and Engineering (SIMaP), Université Grenoble Alpes, CNRS, Grenoble INP, Grenoble, France
-
Stéphane CROS : Researcher, - Department of Solar Technologies, Université Grenoble Alpes, French Alternative Energies and Atomic Energy Commission (CEA), Le Bourget-du-Lac, France
-
Aubin PARMENTIER : Ph.D. Candidate, - Île-de-France Photovoltaic Institute (IPVF) UMR CNRS 9006, Grenoble Laboratory of Materials and Engineering Physics (LMGP) UMR CNRS 5628, France
-
Hugo PATUREAU : Ph.D. student, - Laboratory of Materials and Processes Science and Engineering (SIMaP), Université Grenoble Alpes, CNRS, Grenoble INP, Grenoble, France
INTRODUCTION
Environmental barriers are thin layers or thin-film architectures designed to limit mass transfer between an object and its environment. Their function is to slow the penetration of gases such as water vapor, oxygen, or carbon dioxide, or, conversely, to prevent the loss of volatile compounds contained within the protected system. These properties are essential for ensuring the performance, lifespan, and reliability of many products, ranging from food packaging to the most sensitive electronic devices.
Among the available thin-film deposition technologies, atomic layer deposition (ALD) now holds a special place. Based on a sequence of self-limiting chemical reactions on the surface of materials, this process enables the creation of extremely uniform, conformal, and dense coatings, with precise control of thickness at the nanometer scale. These characteristics give ALD-deposited layers remarkable barrier properties, particularly against water vapor and oxygen, even when the deposited thicknesses are only a few tens of nanometers.
The use of ALD for barrier applications has expanded across a wide range of industrial sectors. It is particularly relevant for microelectronic components, organic light-emitting diodes (OLEDs), photovoltaic cells, and food and cosmetic packaging. The ability to deposit layers at low temperatures on flexible or temperature-sensitive substrates is an additional advantage for these applications.
This article presents the fundamental principles governing gas permeation through materials and the main methods for characterizing barrier properties. It then describes the specific features of the ALD process as applied to encapsulation, the materials commonly used, and the growth mechanisms on different substrates. Finally, it analyzes the relationships between process parameters and the resulting barrier performance, before illustrating the industrial prospects of this technology through several representative application examples.
Key Points
Field: fabrication techniques and characterization.
Degree of technology diffusion: growth.
Technologies involved: ALD, PEALD, SALD, MLD.
Application areas: microelectronics, photovoltaics, packaging, OLEDs.
Major French players:
CEA;
Encapsulix;
STMicroelectronics.
Other global players: Samsung, LG, Merck, Panasonic, Novaled, Sumitomo, Universal Display Corporation, Osram, Konica Minolta, Sony.
Exclusive to subscribers. 97% yet to be discovered!
Already subscribed? Log in!
KEYWORDS
encapsulation | Atomic Layer Deposition (ALD) | Gas barrier coatings | gas permeation
EDITIONS
Other editions of this article are available:
- Archived version Oct 2016 1 by Tony MAINDRON, Messaoud BEDJAOUI
CAN BE ALSO FOUND IN:
Environmental barriers by ALD
Background
Bibliography
Exclusive to subscribers. 97% yet to be discovered!
Already subscribed? Log in!
Article included in this offer
"Technological innovations"
(
201 articles
)
Updated and enriched with articles validated by our scientific committees
A set of exclusive tools to complement the resources
