PIN OLEDs — Improved structures and materials to enhance device lifetime

Abstract

Currently, three issues are identified that decide upon the commercial success of organic light-emitting diodes (OLEDs), both in display and lighting applications: power efficiency, lifetime, and price competitiveness. PIN OLEDs are widely seen as the preferred way to maximize power efficiency. Here, it is reported that this concept also delivers the world longest lifetimes. For a highly efficient deep-red PIN OLED, a half-lifetime of 25,000 hours for a starting brightness of 10,000 cd/m 2 and a minimal voltage increase over lifetime is reported. This value corresponds to more than 1 × 10 6 hours at 1000 cd/m 2 using an exponent of n = 1.7, which was measured by driving the OLEDs at different starting luminances. Because there is no initial luminance drop, these PIN OLEDs also exhibit a very high 80% lifetime (>300,000 hours at 1000 cd/m 2 ). New record lifetime values for blue and green will be reported as well. Additionally, further topics that have impact on the production yield and cost such as the newly developed air-stable organic n-doping material NDN-26 and top-emitting structures will be discussed.

Organic light-emitting diodes using 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane as p-type dopant

“…1-4 Recently, the development of the OLED technology is focused mainly on the direction of lowering operation voltage to reduce power consumption, 5,6 improving color purity 7,8 and lifetime, [9][10][11] as well as increasing device efficiency via triplet emitters. 12,13 In order to lower the operation voltage and power consumption, the concept of electrical doping, which is adopted from inorganic semiconductors, is widely employed.…”

60.1: Invited Paper: Tandem Hybrid White OLED Devices with Improved Light Extraction

“…The lifetime was tested by operating the devices under constant current drive and monitoring the luminous output continuously. Because of the excessive time needed to test long-lived devices, an accelerated test procedure was used [11]. The device was tested at several brightness levels and the data were extrapolated to yield the expected lifetime value at 1,000 cd/m 2 .…”

Organic Semiconductor Electroluminescent Materials

“…However, the dopant is sensitive to air, and can only be handled in an inert atmosphere. Later, they announced an air stable n-type dopant NDN26 [80,81], although the material structure has not been disclosed.…”