XU Qin-qin, ZHANG Ji-dong, CHEN Jiang-shan, MA Dong-ge, YAN Dong-hang. Induced Crystallization of Hole Transport Layer by Buffer Layer in Organic Light Emitting Diodes[J]. Chinese Journal of Luminescence, 2005,26(1): 89-94
XU Qin-qin, ZHANG Ji-dong, CHEN Jiang-shan, MA Dong-ge, YAN Dong-hang. Induced Crystallization of Hole Transport Layer by Buffer Layer in Organic Light Emitting Diodes[J]. Chinese Journal of Luminescence, 2005,26(1): 89-94DOI:
Crystallization of organic thin films is one of the main degradation mechanisms of organic light emitting diodes (OLEDs). The induced crystallization of N
N′-di(naphthalene-1-yl) N
N′-diphenyl-benzidine (NPB) thin films by copper phthalocyanine (CuPc) buffer layer with different thickness and nucleus sizes was studied by atomic force microscopy (AFM) and wide angle X-ray diffraction (WAXRD). It was found that the NPB with CuPc as buffer layer crystallized more easily than that without CuPc buffer layer
and CuPc films can induce the crystallization of NPB films. These results may provide evidence that the long-term degradation of an OLED with CuPc as buffer layer can be partially attributed to the crystallization of the hole-transporting layer NPB induced by CuPc.