TY - JOUR
T1 - Molecular order, charge injection efficiency and the role of intramolecular polar bonds at organic/organic heterointerfaces
AU - Wang, Y.
AU - Matsushima, T.
AU - Murata, H.
AU - Fleurence, A.
AU - Yamada-Takamura, Y.
AU - Friedlein, R.
N1 - Funding Information:
We acknowledge fruitful discussions with Yuanping Yi (School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, USA). This work has been supported by Grants-in-Aid for Scientific Research of Japan (Nos. 21760005 , 20241034 , and 20108012 ), by the MARUBUN Foundation and by the Japan Society for the Promotion of Science (JSPS) through its Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program).
PY - 2012/10
Y1 - 2012/10
N2 - The effect of orientational changes in thin films of the non-crystalline hole transport material α-N-N′-diphenyl N-N″-bis(1 naphthayl)-1,1′-biphenyl-4,4′-diamine (α-NPD) on the energy level alignment and the film electronic structure has been investigated by angle-resolved ultraviolet photoelectron spectroscopy and related to the transport characteristics of hole-only devices. Changes in the anisotropic α-sexithiophene (α-6T) substrate from a "standing" to a "flat" molecular orientation induced by mechanical rubbing lead to molecular order and a preferential orientation in subsequently deposited thin α-NPD films and cause a reduction of the charge injection barrier at the organic/organic interface. The results show that the height of this barrier is determined by the surface dipoles of the individual organic films that relate to the orientation of intramolecular polar bonds at the interface.
AB - The effect of orientational changes in thin films of the non-crystalline hole transport material α-N-N′-diphenyl N-N″-bis(1 naphthayl)-1,1′-biphenyl-4,4′-diamine (α-NPD) on the energy level alignment and the film electronic structure has been investigated by angle-resolved ultraviolet photoelectron spectroscopy and related to the transport characteristics of hole-only devices. Changes in the anisotropic α-sexithiophene (α-6T) substrate from a "standing" to a "flat" molecular orientation induced by mechanical rubbing lead to molecular order and a preferential orientation in subsequently deposited thin α-NPD films and cause a reduction of the charge injection barrier at the organic/organic interface. The results show that the height of this barrier is determined by the surface dipoles of the individual organic films that relate to the orientation of intramolecular polar bonds at the interface.
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U2 - 10.1016/j.orgel.2012.05.038
DO - 10.1016/j.orgel.2012.05.038
M3 - Article
AN - SCOPUS:84862986963
SN - 1566-1199
VL - 13
SP - 1853
EP - 1858
JO - Organic Electronics: physics, materials, applications
JF - Organic Electronics: physics, materials, applications
IS - 10
ER -