Department of Physics and Astronomy and London Centre for Nanotechnology, University College London, London WC1E 6BT, UK.
ACS Nano. 2010 Jul 27;4(7):3921-6. doi: 10.1021/nn100782w.
The development of molecular nanostructures plays a major role in emerging organic electronic applications, as it leads to improved performance and is compatible with our increasing need for miniaturization. In particular, nanowires have been obtained from solution or vapor phase and have displayed high conductivity or large interfacial areas in solar cells. In all cases however, the crystal structure remains as in films or bulk, and the exploitation of wires requires extensive postgrowth manipulation as their orientations are random. Here we report copper phthalocyanine (CuPc) nanowires with diameters of 10-100 nm, high directionality, and unprecedented aspect ratios. We demonstrate that they adopt a new crystal phase, designated eta-CuPc, where the molecules stack along the long axis. The resulting high electronic overlap along the centimeter length stacks achieved in our wires mediates antiferromagnetic couplings and broadens the optical absorption spectrum. The ability to fabricate ultralong, flexible metal phthalocyanine nanowires opens new possibilities for applications of these simple molecules.
分子纳米结构的发展在新兴的有机电子应用中起着重要作用，因为它可以提高性能，并且符合我们日益增长的小型化需求。特别是，已经从溶液或气相中获得了纳米线，并在太阳能电池中显示出高导电性或大的界面面积。然而，在所有情况下，晶体结构仍然与薄膜或体相相同，并且由于其取向是随机的，因此需要对纳米线进行广泛的后生长处理。在这里，我们报告了直径为 10-100nm 的具有高方向性和前所未有的纵横比的铜酞菁（CuPc）纳米线。我们证明它们采用了一种新的晶体相，称为 eta-CuPc，其中分子沿长轴堆积。在我们的纳米线中，厘米长度堆叠的电子重叠实现了高电子重叠，从而介导反铁磁耦合并拓宽了光学吸收光谱。制造超长、柔韧的金属酞菁纳米线的能力为这些简单分子的应用开辟了新的可能性。
