Department of Physics, National Tsing Hua University, 101 Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan.
Nat Commun. 2013;4:2925. doi: 10.1038/ncomms3925.
Organic-metal interfaces are key elements in organic-based electronics. The energy-level alignment between the metal Fermi level and the molecular orbital levels determines the injection barriers for the charge carriers at the interfaces, which are crucial for the performance of organic electronic devices. Dipole formation at the interfaces has been regarded as the main factor that affects the energy-level alignment. Several models have been proposed for the mechanism of dipole formation in the context of the interface between organic molecules and a bulk metal crystal surface, at which surface states were mostly used to probe the interfacial properties. Here we report that when the bulk metal crystal is replaced by a uniform metal thin film, the resulting two-dimensional quantum-well states will be able to not only probe but also modify the interfacial electronic structures, such as gap states, that have no counterpart at the organic-bulk crystal interface.
有机-金属界面是有机电子学中的关键元素。金属费米能级和分子轨道能级之间的能级对准决定了界面处载流子的注入势垒，这对有机电子器件的性能至关重要。界面处形成的偶极子被认为是影响能级对准的主要因素。已经提出了几种模型来解释有机分子与体相金属晶体表面之间界面处偶极子形成的机制，其中表面态主要用于探测界面性质。在这里，我们报告了当体相金属晶体被均匀的金属薄膜取代时，所产生的二维量子阱态不仅能够探测，而且能够修饰界面电子结构，例如在有机-体相晶体界面上没有对应物的间隙态。
