Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (8): 1597-1601.doi: 10.3866/PKU.WHXB201505291

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Mesoscopic Optical Structure to Enhance the Out-Coupling Efficiency of Blue Top OLED

Yaohsien. CHUNG1,Mengying. BIAN1,Mingxiao. ZHANG1,Saisai. CHU1,Zhijian. CHEN1,2,3,Qihuang. GONG1,Lixin. XIAO1,2,3,*()   

  1. 1 State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, P. R. China
    2 Beijing Engineering Research Center for Active Matrix Display, Beijing 100871, P. R. China
    3 New Display Device and System Integration Collaborative Innovation Center of the West Coast of the Taiwan Strait, Fuzhou 350002, P. R. China
  • Received:2015-04-13 Published:2015-08-12
  • Contact: Lixin. XIAO E-mail:lxxiao@pku.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(61177020, 11121091);National Basic Research Program ofchina(2009CB30504)

Abstract:

In this study, mesoscopic optical structured 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenyl-1, 10-phenanthrolin (bathocuproine, BCP) film was formed to enhance the out-coupling efficiency of a top blue organic light-emitting device (OLED). Based on the refractive index matching layer of BCP on the electrode, the light can be extracted through waveguide mode. Owing to the low glass transition temperature (Tg) of BCP, which easily self-aggregates in a specific environment (controlled temperature and humidity), a mesoscopic optical structure was obtained in 3 h after film formation. Through the nano-aggregated structure, the surface plasmon polariton (SPP) mode can match the free optic field. The efficiency of the device was enhanced: the max brightness increased from 4500 to 9840 cd·m-2 and the external quantum efficiency (EQE) increased from 0.42% to 1.14%. This leads to a 2.7-fold enhancement of top emission devices. Moreover, the EL spectra of the devices are also optimized by a blue-shift of 12 nm.

Key words: Mesoscopic optical structure, Organic light-emitting device, Blue light, Top emission, External quantum efficiency

MSC2000: 

  • O644