고효율 CBP:Ir(ppy)3-PhOLEDs의 제작과 특성 연구
Fabrication and Characterization of High Efficiency CBP:Ir(ppy)3-PhOLEDs
1
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
고효율 녹색 인광 유기발광다이오드를 개발하기 위해 소자 구조를 ITO/2-TNATA /NPB/ TCTA/CBP:7%Ir(ppy)3/BCP/SFC-137/LiF/Al로 설계·제작하고 그 전계발광 특성을 평가하였다. 소자 제 작에서 발광 호스트의 두께를 150Å~350Å 범위로 변화시켜, 전계발광 특성을 비교해 본 결과, CBP 두께가 약 300Å 부근일 때 가장 우수한 휘도 특성이 얻어졌다. 전류 효율은 CBP 두께가 300Å~350Å 범위일 때 거 의 포화되어 최대로 나타났다. CBP(300Å):7%Ir(ppy)3-EML 층을 갖는 PhOLED(phosphorescent organic light emitting diode)의 전류 밀도, 휘도, 그리고 전류 효율은 10V의 인가전압에서 각각 40 mA/cm2, 10000 cd/m2, 25 cd/A로 나타났다. 또한 이 소자의 최대 전류효율은 160 cd/m2 의 휘도 상태에서 40.5 cd/A로 나 타났다. 발광 스펙트럼은 512 nm의 중심 파장과 약 60nm의 FWHM(Full Width Half Maximum)을 나타내 었으며, CIE (Commission Internationale de I'Eclairage) 도표 상에서 색 좌표는 (0.28, 0.63)으로 나타났다.
Abstract
New devices with the structure of ITO/2-TNATA/NPB/TCTA/CBP:7%Ir(ppy)3/BCP/SFC-137/LiF/Al were designed and fabricated to develop high efficiency green phosphorescent organic light emitting diodes and their electroluminescence properties were evaluated.Among the devices with different thicknesses of CBP in a range of 150~350, the best luminance was obtained in the device with 300-thick CBP host. Nearly saturated current efficiencies indicates that the maximum efficiency value can be obtained with CBP thicknesses of 300~350. The current density, luminance, and current efficiency of the PhOLED(phosphorescent organic light emitting diode) with CBP(300):7%Ir(ppy)3-emissive layer at an applied voltage of 10V were 40 mA/cm2, 10000 cd/m2, and 25 cd/A, respectively. The maximum current efficiency was 40.5 cd/A under the luminance of 160 cd/m2. The peak wavelength and FWHM(full width at half maximum) in the electroluminescence spectral were 512nm and 60nm, respectively. The color coordinate was (0.28, 0.63) on the CIE (Commission Internationale de I'Eclairage) chart.
참고문헌 (13)
- C. W. Tang, "Organic electroluminescent diodes", J. of Appl. Phys. Lett, 51(93), pp.913~915 (1987)
- Zakya H. Kafafi, "Organic Electroluminescence", pp.274~286 (2005), Taylor & Francis
- John L. Vossen, "Thin Film Process", pp.501~564 (2002), Academic Press
- D. C. Shin, "The improving technology of optical properties on OLED", Info. Dis, 5(4), pp.13~17 (2005)
- M. A. Baldo, "Highly efficient phosphorescent emission from organic electroluminescent devices", Nature, 395, pp.151~ (1998)
- 강원호, "유기EL 디스플레이 기초와 응용", pp.105~ (2006), 성안당
- Chihaya Adachi, "Nearly 100% internal phosphorescence efficiency in an organic light emitting device", J. of Appl. Physics, 90, pp.5048~ (2001)
- B.J. Chen, "Phosphorescent organic light-emitting devices with in situ postgrowth annealed organic layers", Materials Science and Engineering B, 139, pp.192~196 (2007)
- K.i Goushi, "Unusual phosphorescence characteristics of Ir (ppy)3 in a solid matrix at low temperatures", Jpn. J. of. Appl. Phys. Lett, 43, pp.937~939 (2004)
- J. Sun, "Investigation of high-efficiency electrophosphorescent organic light-emitting diodes with double-emission layers", SID 07, pp.826~ (2007)
- S.H. Kim, "Triple host engineering for triplet exciton management in phosphorescent organic light-emitting diodes", J. of Appl. Phys. Lett, 103, pp.054502~ (2008)
- M.A. Khan, "Highly efficient organic electroluminescent diodes realized by efficient charge balance with optimized electron and hole transport layers", Solid State Communications, 144, pp.343~346 (2007)
- 장지근, "유기전자공학", pp.314~ (2006), 청문각