论文信息 - Stability of polymer light-emitting diodes

Stability of polymer light-emitting diodes

Abstract In this paper, we report on the lifetime of polymer LEDs fabricated at Philips Research. For single-layer LEDS, we find that the operational lifetime in nitrogen gas is limited by the stability of the indium-tin-oxide (ITO) anode. By using a polymeric capping layer for the ITO, we obtain more stable devices. In air, the lifetime is limited by black spot formation. Small pinholes in the cathode layer are the origins of the black spots. Water or oxygen may diffuse through these pinholes and react with the cathode, causing degradation. By encapsulating the devices we can prevent black spot formation. Our present 8 cm2 devices have lifetimes of many thousands of hours at daylight visibility under ambient conditions.

[1] C. C. Wu,et al. Surface modification of indium tin oxide by plasma treatment: An effective method to improve the efficiency, brightness, and reliability of organic light emitting devices , 1997 .

[2] Akira J. Ikushima,et al. Observation of degradation processes of Al electrodes in organic electroluminescence devices by electroluminescence microscopy, atomic force microscopy, scanning electron microscopy, and Auger electron spectroscopy , 1994 .

[3] Miller,et al. Defect quenching of conjugated polymer luminescence. , 1994, Physical review letters.

[4] Marie Angelopoulos,et al. Polymeric anodes for improved polymer light-emitting diode performance , 1997 .

[5] H. Antoniadis,et al. Formation and growth of black spots in organic light‐emitting diodes , 1996 .

[6] Siegfried Karg,et al. Increased brightness and lifetime of polymer light-emitting diodes with polyaniline anodes , 1996 .

[7] S. Morrison,et al. Semiconductor gas sensors , 1985 .