Carrier Transport Behaviour of Molecularly Doped Poly (N-Vinylcarbozole) in Polymer Light-Emitting Diodes
CHEN Xiao-Hong1,2,3, XU Zheng1,2, HOU Yan-Bing1, LIU Shu-Man1, TENG Feng1, XU Xu-Rong1,2,3
1Institute of Optoelectronic Technology, Northern Jiaotong University, Beijing 100044
2Changchun Institute of Optics and Fine Mechanism and Physics, Chinese Academy of Sciences, Changchun 130021
3Institute of Material Physics, Tianjin University of Technology, Tianjin 300191
Carrier Transport Behaviour of Molecularly Doped Poly (N-Vinylcarbozole) in Polymer Light-Emitting Diodes
1Institute of Optoelectronic Technology, Northern Jiaotong University, Beijing 100044
2Changchun Institute of Optics and Fine Mechanism and Physics, Chinese Academy of Sciences, Changchun 130021
3Institute of Material Physics, Tianjin University of Technology, Tianjin 300191
Abstract： Single-layer polymer light-emitting diodes (PLEDs) are prepared from blends of poly (N-vinylcarbozole) (PVK) doped with tris (8-hydroxy-quinoline) aluminum (Alq3) of 2 wt% (sample a) and 0.2 wt% (sample b). The onset of PVK transient electroluminescence (EL) is delayed with respect to that of Alq3 in sample a under pulsed excitation, While the EL onset of Alq3 and PVK in sample b are simultaneous. The total carrier mobility of Alq3-rich regions in sample a is larger than that of PVK-rich regions. However, the total carrier mobility is homogenous in sample b. The phase image of atomic force microscopy and photoluminescence spectra of sample a and sample b indicate that the separated phase of samples a and b exists in PVK-rich regions and Alq3-rich regions. The variance of the doping concentration and separated phase in blends results in the different carrier transport mobility of Alq3-rich regions and PVK-rich regions.
2002, Vol. 19 
