Formation of perfect ohmic contact at indium tin oxide/N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine interface using ReO3.
A perfect ohmic contact is formed at the interface of indium tin oxide (ITO) and N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB) using ReO3 as the interfacial layer. The hole injection efficiency is close to 100% at the interface, which is much higher than those for interfacial layers of 1,4,5,8,9,11-hexaazatripheylene hexacarbonitrile (HAT-CN) and MoO3. Interestingly, the ReO3 and MoO3 interfacial layers result in the same hole injection barrier, ≈0.4 eV, to NPB, indicating that the Fermi level is pinned to the NPB polaron energy level. However, a significant difference is observed in the generated charge density in the NPB layer near the interfacial layer/NPB interface, indicating that charge generation at the interface plays an important role in forming the ohmic contact.
WCU Hybrid Materials Program, Department of Materials Science and Engineering and the Center for Organic Light-Emitting Diodes, Seoul National University, Seoul 151-744, South Korea.
Seung-Jun
SJ
Yoo
Graduated Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei 106, Taiwan.
Jung-Hung
JH
Chang
WCU Hybrid Materials Program, Department of Materials Science and Engineering and the Center for Organic Light-Emitting Diodes, Seoul National University, Seoul 151-744, South Korea.
Jeong-Hwan
JH
Lee
Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, South Korea.
Chang-Ki
CK
Moon
Graduated Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei 106, Taiwan.
Chih-I
CI
Wu
1] WCU Hybrid Materials Program, Department of Materials Science and Engineering and the Center for Organic Light-Emitting Diodes, Seoul National University, Seoul 151-744, South Korea [2] Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, South Korea.
Jang-Joo
JJ
Kim