P‐6.3: The Impact of Thin Film Shadow on Organic Light ‐ Emitting Diode Flexible Encapsulation

Abstract

Organic Light ‐ Emitting Diode (OLED) displays are characterized by ultra‐thin, ultra‐clear, spontaneous light, high definition, low cost of preparation and flexible display. In recent years, flexible OLED has become a hot topic in flat panel display industry. Thin film encapsulation (TFE) plays a key role in flexible OLED [1,2].The inorganic layer part of flexible encapsulation is generally prepared by plasma enhanced chemical vapor deposition (PECVD) for SiNx or SiON. The quality of inorganic thin film directly affects the service life‐time of OLED devices, It is mainly influenced by Particle, shadow effect, stress, refractive index, thickness and other factors, among which several factors besides the shadow effect of thin films have been widely studied. As we all know, shadow effect exists in any film, but for inorganic layer in flexible encapsulation, whether the shadow effect of the thin film will affect its encapsulation effect. This paper will explore the influence of thin film shadow effect on encapsulation effect and device life. The shadow of the thin film varies from a few microns to several hundred microns in the existing devices. In this paper, a special device structure design is used to control the size of film shadow. We will produce OLED samples of different shadow sizes. It can be seen from the test results in the 85 °C and 85% RH for 240h that the smaller the Shadow of PECVD thin film is, the less likely it is to lose efficacy.In this paper, by effectively controlling the shadow size of the thin film, flexible OLED devices with better performance and longer service life are obtained. At last, more tests are needed in order to get a more precise investigation.