title: Luminance uniformity study of OLED lighting panels depending on OLED device structures.
abstract: This paper describes the luminance uniformity of OLED lighting panels depending on OLED device structures of single emission layer (single-EML), 2-tandem, and 3-tandem. The luminance distribution is evaluated through the circuit simulation and the fabricated panel measurement. In the simulation results with yellow-green color panels of 30 × 80 mm2emission area, a 3-tandem structure shows the lowest non-uniformity (1.34% at 7.5V), compared to single-EML (5.67% at 2.8V) and 2-tandem (2.78% at 5.3 V) structures at 1,000 cd/m2. The luminance non-uniformity is germane to the OLED conductance showing that the high luminance-current efficiency is of the most importance to achieve the uniform voltage and luminance distribution. In measurement, a 3-tandem structure also achieves the most uniform luminance distribution with non-uniformity of 4.1% while single EML and 2-tandem structures accomplish 9.6%, and 6.4%, respectively, at ~1,000 cd/m2. In addition, the simulation results ensure that a 3-tandem structure panel is allowed to be enlarged the panel size up to about 5,000 mm2for lower luminance non-uniformity than 10% without any auxiliary metal electrodes.
authors.forename: Hyeong Woo
authors.initials: HW
authors.lastname: Bae
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Son
authors.forename: Byoung Yeop
authors.initials: BY
authors.lastname: Kang
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Hyoungsik
authors.initials: H
authors.lastname: Nam
authors.forename: Jang Hyuk
authors.initials: JH
authors.lastname: Kwon