Method of Measuring Ultralow Water Vapor Permeation for OLED Displays

It is well known that proper encapsulation is crucial for the lifetime of organic LED (OLED) displays. With the development of better and better barrier coatings and perimeter seals, it has now become very desirable to be able to precisely measure the rate of water vapor and oxygen permeation through barrier coatings and perimeter sealing. This paper demonstrates a new permeation measurement method that uses tritium-containing water (HTO) as tracer materials. The theoretical detection limit is 2.4×10^-7 g/(m²·day).