[OPTICAL REVIEW Vol. 19, No. 2 (2012) 82-85]
© 2012 The Japan Society of Applied Physics

Effect of Encapsulation Technology on Organic Light Emitting Diode Lifetime

Jian ZHONG, Zhuo GAO*, Juan GAO, Ke DAI, and Jiule CHEN

State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, P. R. China

(Received April 30, 2011; Accepted January 12, 2012)

A kind of green organic light-emitting diodes (OLED) was prepared via vacuum thermal evaporation, of which the multilayer structure was indium–tin oxide (ITO)/copper–phthalocyanine (CuPc) (200 Å)/N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD) (600 Å)/N'-diphenyl-N,N'-tris(8-hydroxyquinoline) aluminium (Alq3) (400 Å):10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-(l)benzopyropyrano(6,7,8-i,j)quinolizin-11-one (C545T) (2%)/Alq3 (200 Å)/LiF (10 Å)/Al (1000 Å). And we used both traditional glass encapsulation and thin film encapsulation (TFE) technologies to protect the device, reducing impact of vapor and oxygen. Organic film offered an excellent surface morphology, while inorganic film was nearly a perfect barrier to vapor and oxygen. Both of them constituted the encapsulation unit of TFE. According to the results of acceleration life test, the operation lifetime of device using TFE was 22% less than that of device using traditional glass cap encapsulation. So, the technology of TFE should be optimized further, and the quality of TFE needs a great improvement. There is a long way to go and a lot of hard work before realizing flexible display with OLED, but the dream will be true one day.

Key words: OLED, glass cap, TFE, barrier layer, operation lifetime

*E-mail address: gaozhuo0606@foxmail.com