Abstract： A series of organic light-emitting diodes (OLEDs) have been fabricated with different thickness of the tin (Sn) layer. The structure of the devices is indium-tin oxide (ITO)/copper phthalocyanine (CuPc)(12 nm)/N, N'-diphenyl-N, N'-bis(1-naphthyl)-(1,1'-biphenyl)-4, 4'-diamine (NPB) (60 nm)/tris-(8-hydroxyquinoline)aluminum (Alq3) (60 nm)/Sn/aluminum (Al)(120 nm). It is found that compared to OLEDs with only Al cathode, both the electron injection efficiency and electroluminescence are improved when the thickness of the Sn layer is properly chosen. The maximum efficiency and brightness of the devices with Sn (2.1 nm)/Al and Al cathode are 0.54lm/W and 9800cd/m2, 0.26lm/W and 3000cd/m2, respectively. One possible explanation to this phenomenon is that the enhancement of the electron density of the Sn layer due to the electron transfer from the Al to the Sn layer leads to the improvement of the electron injection efficiency and electroluminescence.
LI Feng;CHENG Gang;FENG Jing;LIU Shi-Yong. Enhanced Electron Injection Efficiency and Electroluminescence
in Organic Light-Emitting Diodes by Using an Sn/Al Cathode[J]. 中国物理快报, 2002, 19(10): 1534-1536.
LI Feng, CHENG Gang, FENG Jing, LIU Shi-Yong. Enhanced Electron Injection Efficiency and Electroluminescence
in Organic Light-Emitting Diodes by Using an Sn/Al Cathode. Chin. Phys. Lett., 2002, 19(10): 1534-1536.
2002, Vol. 19 
