Long-lived and highly efficient green and blue phosphorescent emitters and device architectures for OLED displays

Christian Eickhoff; Peter Murer; Thomas Geßner; Jan Birnstock; Michael Kröger; Zungsun Choi; Soichi Watanabe; Falk May; Christian Lennartz; Ilona Stengel; Ingo Münster; Klaus Kahle; Gerhard Wagenblast; Hannah Mangold

doi:10.1117/12.2199079

22 September 2015 Long-lived and highly efficient green and blue phosphorescent emitters and device architectures for OLED displays

Christian Eickhoff, Peter Murer, Thomas Geßner, Jan Birnstock, Michael Kröger, Zungsun Choi, Soichi Watanabe, Falk May, Christian Lennartz, Ilona Stengel, Ingo Münster, Klaus Kahle, Gerhard Wagenblast, Hannah Mangold

Author Affiliations +

Proceedings Volume 9566, Organic Light Emitting Materials and Devices XIX; 95662N (2015) https://doi.org/10.1117/12.2199079
Event: SPIE Organic Photonics + Electronics, 2015, San Diego, California, United States

Abstract

In this paper, two OLED device concepts are introduced. First, classical phosphorescent green carbene emitters with unsurpassed lifetime, combined with low voltage and high efficiency are presented and the associated optimized OLED stacks are explained. Second, a path towards highly efficient, long-lived deep blue systems is shown. The high efficiencies can be reached by having the charge-recombination on the phosphorescent carbene emitter while at the same time short emissive lifetimes are realized by fast energy transfer to the fluorescent emitter, which eventually allows for higher OLED stability in the deep blue.

Device architectures, materials and performance data are presented showing that carbene type emitters have the potential to outperform established phosphorescent green emitters both in terms of lifetime and efficiency. The specific class of green emitters under investigation shows distinctly larger electron affinities (2.1 to 2.5 eV) and ionization potentials (5.6 to 5.8 eV) as compared to the "standard" emitter Ir(ppy)₃ (5.0/1.6 eV). This difference in energy levels requires an adopted OLED design, in particular with respect to emitter hosts and blocking layers. Consequently, in the diode setup presented here, the emitter species is electron transporting or electron trapping.

For said green carbene emitters, the typical peak wavelength is 525 nm yielding CIE color coordinates of (x = 0.33, y = 0.62). Device data of green OLEDs are shown with EQEs of 26 %. Driving voltage at 1000 cd/m² is below 3 V. In an optimized stack, a device lifetime of LT₉₅ > 15,000 h (1000 cd/m²) has been reached, thus fulfilling AMOLED display requirements.

Citation Download Citation

Christian Eickhoff, Peter Murer, Thomas Geßner, Jan Birnstock, Michael Kröger, Zungsun Choi, Soichi Watanabe, Falk May, Christian Lennartz, Ilona Stengel, Ingo Münster, Klaus Kahle, Gerhard Wagenblast, and Hannah Mangold "Long-lived and highly efficient green and blue phosphorescent emitters and device architectures for OLED displays", Proc. SPIE 9566, Organic Light Emitting Materials and Devices XIX, 95662N (22 September 2015); https://doi.org/10.1117/12.2199079

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available