1616-3028/asset/2126_centre.gif?v=1&s=c88ccad5117044f38366989c886e57ea3f100c56)
Full Paper
The Mechanism of Charge Generation in Charge-Generation Units Composed of p-Doped Hole-Transporting Layer/HATCN/n-Doped Electron-Transporting Layers
Article first published online: 16 DEC 2011
DOI: 10.1002/adfm.201102212
Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Additional Information
How to Cite
Lee, S., Lee, J.-H., Lee, J.-H. and Kim, J.-J. (2012), The Mechanism of Charge Generation in Charge-Generation Units Composed of p-Doped Hole-Transporting Layer/HATCN/n-Doped Electron-Transporting Layers. Adv. Funct. Mater., 22: 855–860. doi: 10.1002/adfm.201102212
Publication History
- Issue published online: 15 FEB 2012
- Article first published online: 16 DEC 2011
- Manuscript Revised: 10 NOV 2011
- Manuscript Received: 17 SEP 2011
- Abstract
- Article
- References
- Cited By
Keywords:
- charge-generation efficiency;
- organic n–n heterojunctions;
- electron transporting layers;
- organic light-emitting diodes
Abstract
The rate-limiting step of charge generation in charge-generation units (CGUs) composed of a p-doped hole-transporting layer (p-HTL), 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HATCN) and n-doped electron-transporting layer (n-ETL), where 1,1-bis-(4-bis(4-methyl-phenyl)-amino-phenyl)-cyclohexane (TAPC) was used as the HTL is reported. Energy level alignment determined by the capacitance–voltage (C–V) measurements and the current density–voltage characteristics of the structure clearly show that the electron injection at the HATCN/n-ETL junction limits the charge generation in the CGUs rather than charge generation itself at the p-HTL/HATCN junction. Consequently, the CGUs with 30 mol% Rb2CO3-doped 4,7-diphenyl-1,10-phenanthroline (BPhen) formed with the HATCN layer generates charges very efficiently and the excess voltage required to generate the current density of ±10 mA cm−2 is around 0.17 V, which is extremely small compared with the literature values reported to date.