Fine-Tuning the Electrostatic Properties of an Alkali-Linked Organic Adlayer on a Metal Substrate
Fine-Tuning the Electrostatic Properties of an Alkali-Linked Organic Adlayer on a Metal Substrate
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DOI：
10.1021/nn403274s
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发表时间：
2013-09-01
期刊：
影响因子：
17.1
通讯作者：
De Vita, Alessandro
中科院分区：
文献类型：
--
作者：
Floris, Andrea;Comisso, Alessio;De Vita, Alessandro
现代有机电子器件的性能通常由金属-有机界面上的电子电平对准来决定。这种特性可以通过在金属相和有机相之间插入稳定的中间层来引入界面静电偶极子来控制。本文利用密度泛函理论研究了碱金属与7,7,8,8-四氰喹诺二甲烷（TCNQ）分子在Ag（100）衬底上共吸附形成的组装结构的静电特性。我们发现界面偶极子的形成受吸附能量、空间约束和电荷转移效应的相互作用调节，因此在TCNQ和不同碱金属中选择化学取代为控制系统静电，特别是微调其工作函数的转变提供了丰富的平台。
The performance of modern organic electronic devices is often determined by the electronic level alignment at a metal-organic Interface. This property can be controlled by introducing an interfacial electrostatic dipole via the insertion of a stable interlayer between the metallic and the organic phases. Here, we use density functional theory to investigate the electrostatic properties of an assembled structure formed by alkali metals coadsorbed with 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on a Ag(100) substrate. We find that the interfacial dipole buildup is regulated by the interplay of adsorption energetics, steric constraints and charge transfer effects, so that choosing chemical substitutions within TCNQ and different alkali metals provides a rich playground to control the systems electrostatics and in particular fine-tune its work-function shift.