Realizing nearly-free-electron like conduction band in a molecular film through mediating intermolecular van der Waals interactions
Realizing nearly-free-electron like conduction band in a molecular film through mediating intermolecular van der Waals interactions
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通过介导分子间范德华相互作用在分子膜中实现近自由电子的导带
DOI：
10.1038/s41467-019-11300-y
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发表时间：
2019-07-29
影响因子：
16.6
通讯作者：
Feng, Min
中科院分区：
文献类型：
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作者：
Cui, Xingxia;Han, Ding;Feng, Min
集体分子物理性质可以通过在材料界面处的模板化从它们的固有特性增强。在这里，我们报告了如何黑磷（BP）基板级联近自由电子（NFE）一样的C60单层的导带。扫描隧道显微镜显示C60最低未占分子轨道（LUMO）带在二维空间中强烈离域，这在分子半导体中是前所未有的。实验和理论分析表明，C60和BP之间的货车范德华力减小了C60之间的距离，导致相互取向，从而优化了π-π波函数的重叠，形成了NFE类带。电子结构和载流子迁移率计算预测，C60的NFE带获得0.53-0.70me（自由电子的质量）的有效质量，载流子迁移率为~200 - 440 cm 2 V − 1 s −1。基底介导的分子间货车德瓦尔斯相互作用提供了一种途径，以提高电荷离域富勒烯和其他有机半导体。
Collective molecular physical properties can be enhanced from their intrinsic characteristics by templating at material interfaces. Here we report how a black phosphorous (BP) substrate concatenates a nearly-free-electron (NFE) like conduction band of a C60monolayer. Scanning tunneling microscopy reveals the C60lowest unoccupied molecular orbital (LUMO) band is strongly delocalized in two-dimensions, which is unprecedented for a molecular semiconductor. Experiment and theory show van der Waals forces between C60and BP reduce the inter-C60distance and cause mutual orientation, thereby optimizing the π-π wave function overlap and forming the NFE-like band. Electronic structure and carrier mobility calculations predict that the NFE band of C60acquires an effective mass of 0.53–0.70me(meis the mass of free electrons), and has carrier mobility of ~200 to 440 cm2V−1s−1. The substrate-mediated intermolecular van der Waals interactions provide a route to enhance charge delocalization in fullerenes and other organic semiconductors.