Colorimetric Characteristics of Green Organic Light-emitting Diodes with Varied Thickness of Emission Layer
The popularity of OLEDs is increasing because of their wide viewing angle, fast response, and high-purity color reproduction without backlighting. This work investigates how the thickness of the emission layer (EML) influences the color stability of the green OLEDs. To investigate their electrical and optical characteristics, Alq3 was used as an emission layer in the green OLEDs. The structure of the devices is ITO (150 nm)/NPB (40 nm)/Alq3 (x nm)/LiF (1 nm)/Al (100 nm) with varied Alq3 thickness of 45, 55, 65, and 75 nm. Characterized high-end CCD camera was used to measure colorimetric characteristics of the green OLEDs. Spectral characteristics were confirmed using a PR-650 Spectra Scan Colorimeter. Their 1931 CIE xy chromaticity coordinates are determined as (0.357, 0.533) to (0.347, 0.516) (x=0.01, y=0.017), which correspond to green tint with increasing driving voltage. The thickness of Alq3 which significantly influences the color of OLEDs thus can be a principal factor affecting their color reproducibility and consistency. The color of these green OLEDs was stabilized when the Alq3 thickness became 65 nm. If the thickness is too thin, the chromaticity coordinates shifted toward blue region with increasing driving voltage. For these green OLEDs, current efficiency, power efficiency, and luminance were 5.563 cd/A, 1.205 lm/W, and 5665 cd/m2 at 100mA, respectively.
Youn Goo Kim Du Yeong Lee Jung-Hyun Seo Kyeong-Kap Paek
Department of Electronic Engineering, Daejin University Pocheon, Gyeonggi-do, Korea Department of Electronic Engineering, Daejin University Pocheon, Gyeonggi-do, Korea
国际会议
The 31st International Congress on Imaging Science(第31届国际影像科学大会 ICIS2010)
北京
英文
755-757
2010-05-12（万方平台首次上网日期，不代表论文的发表时间）