A new method for measuring ultra-low water-vapor permeation for OLED displays

It is well known that proper encapsulation is crucial for the lifetime of organic light-emitting-diode (OLED) displays. With the development of increasingly 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 a tracer material. The theoretical detection limit of this direct method is 2.4 x 10(-8) g/(m(2)-day).