57.1: Invited Paper: Flexible OLEDs for Lighting Applications

Abstract

In this paper we will discuss the key technologies needed for fabricating flexible OLED lighting panels with specific focuses on flexible substrates, high efficacy phosphorescent materials and thin film encapsulation technologies. We will report results of 15 cm x 15 cm phosphorescent OLED (PHOLED TM ) flexible lighting panels using flexible substrates.

Synthesis of Superheat-Resistant Polyimides with High Tg and Low Coefficient of Thermal Expansion by Introduction of Strong Intermolecular Interaction

“…Flexible active-matrix organic light-emitting-diode (AMOLED) devices based on low-temperature polysilicon thin-film transistors (LTPS TFTs) have attracted intensive attention because of their great potential as optimal candidates in next-generation displays. − The flexible substrate is a key component for future flexible displays. Materials used to manufacture flexible substrates must possess a high heat resistance, a high dimensional stability, a smooth surface, a good water-vapor transmission rate, a ruggedness, and a chemical resistance. − Unlike the water-vapor transmission rate and chemical resistance, which can be improved by the manufacture of a permeation barrier layer, , the thermal properties, including a high glass-transition temperature ( T g ), a high thermal-decomposition temperature ( T d ), and a low coefficient of thermal expansion (CTE), must be solved by performance improvement of the material itself. According to the conventional LTPS process, the supporting substrate of the LTPS is supposed to withstand temperatures up to at least ∼450 °C .…”

Characterization of light extraction efficiency for WOLEDS with light‐out‐coupling layer

“…Previous studies have shown that η OC of conventional OLEDs is limited at about 20% because total reflection at internal interfaces that light incidents from high refractive index medium to low refractive index medium 11‐13 . The η OC of OLEDs with various light‐out‐coupling (LOC) layers has been already reported 14‐25 . But there is still room for improvement because the η OC of OLEDs is only 30–50%.…”

“…[11][12][13] The η OC of OLEDs with various light-out-coupling (LOC) layers has been already reported. [14][15][16][17][18][19][20][21][22][23][24][25] But there is still room for improvement because the η OC of OLEDs is only 30-50%. Simulation methods for the design of a white OLED (WOLED) structure with a LOC layer are indispensable to improve η OC .…”

66.4: Large‐Sized Flexible Lighting with Highly Efficient OLEDs

“…For fabricating a flexible lighting using OLEDs, there is a method in which an electrode is formed on a thin plastic film or metal foil [4]. An organic layer of an OLED is a thin film (several hundreds nanometers thick) and sensitive to even tiny particle and flaws causing defect; thus, surface flatness of a substrate over which the thin organic layer is deposited is very important.…”