Electromagnetic Simulation and Fabrication of Novel Organic Light-Emitting Devices
Date Issued
2006
Date
2006
Author(s)
Lin, Chun-Liang
DOI
en-US
Abstract
Organic light-emitting devices (OLEDs) have been the subjects of intense investigation in recent years due to their applications in efficient, large-area and full-color displays. In OLEDs, the optical effects of various device structures are critical to device performances. In this thesis, we use the classical electromagnetic theory to model and analyze the emitting characteristic of typical OLEDs, top-emitting OLEDs, and microcavity OLEDs.
Top-emitting organic light-emitting devices (OLEDs) have a few technical merits for active-matrix OLED displays. Generally stronger microcavity effects inherent with top-emitting OLEDs however complicate optimization of device efficiency and other viewing characteristics, such as colors and viewing-angle characteristics. In this thesis, a general methodology for optimizing viewing characteristics of top-emitting OLEDs for display applications is suggested. The effectiveness of the analysis and the methodology is confirmed by experimental results.
Next, optical characteristics of microcavity organic light-emitting devices (OLEDs) having two metal mirrors are systematically examined. Analyses show that a high-reflection back mirror and a low-loss high-reflection exit mirror are essential for such microcavity devices to obtain luminance enhancement relative to conventional noncavity devices. The effects of resonant wavelengths on performances of microcavity organic light-emitting devices by using the rigorous classical electromagnetic model are also examined.
Due to generally low conductivity and low carrier mobilities of organic materials, organic light-emitting devices (OLEDs) are typically optimized for light outcoupling by locating emitters around the first antinode of the metal electrode. In this thesis, by utilizing device structures containing conductive doping, we investigate theoretically and experimentally the influences of the location of emitters relative to the metal electrode on OLED emission, and show that substantial enhancement in light outcoupling (1.2 times) or forward luminance (1.6 times) could be obtained by placing emitters around the second antinode instead of the first antinode. Depending on the detailed condition, the second-antinode device may also give more directed emission as often observed in strong-micrcavity devices yet without suffering color shift with viewing angles.
Subjects
有機發光二極體
微共振腔
模擬
OLED
microcavity
simulation
Type
thesis
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