Controlling energy level offsets in organic/organic heterostructures using intramolecular polar bonds
Controlling energy level offsets in organic/organic heterostructures using intramolecular polar bonds
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DOI：
10.1063/1.3073046
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发表时间：
2009-01-19
影响因子：
4
通讯作者：
Koch, Norbert
中科院分区：
文献类型：
--
作者：
Duhm, Steffen;Salzmann, Ingo;Koch, Norbert
用紫外光电子能谱研究了SiO(2)上并五苯(PEN)和全氟戊烯(PFP)层状共轭分子体系中分子内极性键(IPB)对能级排列的影响。由IPBS引起的PEN和PFP分子的最高占据轨道(HOMO)能级之间存在着1.75 eV的能量偏移。这种大的HOMO能级偏移导致PEN和PFP层之间的分子间能隙较窄，约为0.4 eV。然而，PEN和PFP电子波函数在各层之间没有显著的空间重叠，抑制了层间光学跃迁。
The impact of intramolecular polar bonds (IPBs) on the energy level alignment in layered systems of rodlike conjugated molecules standing on the substrate was investigated for pentacene (PEN) and perfluoropentacene (PFP) on SiO(2) using ultraviolet photoelectron spectroscopy. A remarkably large energy offset of 1.75 eV was found between the highest occupied molecular orbital (HOMO) levels of PEN and PFP caused by IPBs at the surface of standing PFP layers. This large HOMO-level offset results in a narrow intermolecular energy gap of approximately 0.4 eV at the interface between PEN and PFP layers. However, the absence of significant spatial overlap of PEN and PFP electron wave functions across the layers suppresses interlayer optical transitions.