Quantitative analysis of the electrostatic and electronic polarization energies in molecularly mixed films of organic semiconductors
Quantitative analysis of the electrostatic and electronic polarization energies in molecularly mixed films of organic semiconductors
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有机半导体分子混合膜中静电和电子极化能的定量分析
DOI：
10.1103/physrevb.102.125302
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发表时间：
2020
影响因子：
3.7
通讯作者：
H. Yoshida
中科院分区：
文献类型：
--
作者：
Y. Uemura;S. Abd;S. Yanagisawa;H. Yoshida
有机半导体的能级主要由组成分子的分子轨道能量决定。然而，最近的研究表明，能级可以通过具有不同永久四极矩的两个分子的混合比来改变。从混合膜的能量移动的大小和组成分子的永久四极矩之间的良好的相关性，注意到分子四极矩在能量移动中起着重要的作用。利用紫外光电子能谱（UPS）和低能反向光电子能谱（LEIPS）对酞菁锌（ZnPc）和全氟酞菁锌（ZnPc）的混合膜进行了研究。从精确测定的电离能和电子亲合能，我们直接确定了电子极化能和静电能作为混合比的函数。此外，我们研究了分子取向依赖性ofandvalues.is几乎与混合比无关（在混合比范围内差异小于0.2 eV），其中相差多达1.6 eV。结果清楚地表明，能级随混合比的连续移动源于静电相互作用，其主导项是电荷-永久四极相互作用。
The energy levels of organic semiconductors are primarily determined by the molecular orbital energies of constituent molecules. Recent studies have, however, shown that the energy levels can be changed by the mixing ratio of two molecules which have different permanent quadrupole moments. From the good correlation between the magnitude of the mixed film's energy shift and the constituent molecules’ permanent quadrupole moment, it was noted that the molecular quadrupole plays an important role in the energy shift. In this study, ultraviolet photoelectron spectroscopy (UPS) and low-energy inverse photoemission spectroscopy (LEIPS) are applied to the mixed films of zinc phthalocyanine (ZnPc) and perfluorinated ZnPc (), which have permanent quadrupole moments with opposite directions. From the precisely determined ionization energies and electron affinities, we directly determine the electronic polarization energyand electrostatic energyas a function of mixing ratio. Furthermore, we examined the molecular orientation dependence ofandvalues.is almost independent of the mixing ratio (the difference is less than 0.2 eV over the range of mixing ratio) whereasdiffers by as much as 1.6 eV. The result clearly shows that the energy levels’ continuous shift by the mixing ratio originates in the electrostatic interaction, whose leading term is the charge-permanent quadrupole interaction.
影响因子：
56.9
作者：
Schwarze, Martin;Tress, Wolfgang;Leo, Karl
通讯作者：
Leo, Karl