Fermi level pinning at interfaces with tetrafluorotetracyanoquinodimethane (F4-TCNQ): The role of integer charge transfer states

被引:107
作者
Braun, Slawomir [1 ]
Salaneck, William R. [1 ]
机构
[1] Linkoping Univ, IFM, Dept Phys Chem & Biol, S-58183 Linkoping, Sweden
关键词
D O I
10.1016/j.cplett.2007.03.005
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The energy level alignment of vacuum deposited molecular films of tetrafluorotetracyanoquinodimethane (F4-TCNQ) on various substrates has been studied by photoelectron spectroscopy. The interfaces studied span the work function range from 3.45 to 5.8 eV. In this range, the Fermi level of the substrate is pinned in proximity to LUMO level. This indicates that a charge transfer mechanism is responsible for the observed alignment scheme. The photoelectron emission study of sub-monolayer of F4-TCNQ revealed presence of electrons in the charge transfer states at the interface. In this context the electronic structure of neutral and negatively charged F4-TCNQ has been studied theoretically and by photoelectron spectroscopy. (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:259 / 262
页数:4
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