Kratzer M, Szajna K, Wrana D, Belza W, Krok F, Teichert C
Montanuniversitaet Leoben, Franz Josef Straße 18, 8700 Leoben, Austria.
J Phys Condens Matter. 2018 Jul 18;30(28):283001. doi: 10.1088/1361-648X/aac758. Epub 2018 May 23.
Control over organic thin film growth is a central issue in the development of organic electronics. The anisotropy and extended size of the molecular building blocks introduce a high degree of complexity within the formation of thin films. This complexity can be even increased for substrates with induced, sophisticated morphology and anisotropy. Thus, targeted structuring like ion beam mediated modification of substrates in order to create ripples, pyramids, or pit structures provides a further degree of freedom in manipulating the growth morphology of organic thin films. We provide a comprehensive review of recent work on para-hexaphenyl (CH, 6P) as a typical representative of the class of small, rod-like conjugated molecules and rutile TiO(1 1 0) as an example for a transparent oxide electrode to demonstrate the effect of ion beam induced nanostructuring on organic thin film growth. Starting from molecular growth on smooth, atomically flat TiO(1 1 0) (1 × 1) surfaces, we investigate the influence of the ripple size on the resulting 6P thin films. The achieved 6P morphologies are either crystalline nano-needles composed of flat lying molecules or islands consisting of upright standing 6P, which are elongated in ripple direction. The islands' length-to-width ratio can be controlled by tuning the ripples' shape.
控制有机薄膜生长是有机电子学发展中的核心问题。分子构建单元的各向异性和扩展尺寸在薄膜形成过程中引入了高度的复杂性。对于具有诱导的、复杂形态和各向异性的衬底，这种复杂性甚至会增加。因此，诸如离子束介导的衬底改性以产生波纹、金字塔或坑结构等有针对性的结构化，为操纵有机薄膜的生长形态提供了进一步的自由度。我们全面综述了近期关于对六苯基（CH, 6P）（作为小的棒状共轭分子类别的典型代表）和金红石TiO(1 1 0)（作为透明氧化物电极的示例）的研究工作，以证明离子束诱导的纳米结构化对有机薄膜生长的影响。从在光滑的、原子级平整的TiO(1 1 0) (1 × 1)表面上的分子生长开始，我们研究了波纹尺寸对所得6P薄膜的影响。所实现的6P形态要么是由平躺分子组成的结晶纳米针，要么是由直立的6P组成的岛，这些岛在波纹方向上伸长。岛的长宽比可以通过调整波纹的形状来控制。
