Variable-temperature Scanning Probe Microscope for Ultra-High Vacuum

该小组的研究重点是分子纳米科学和界面的表面物理。超高真空的受控环境使高精度表征方法的应用成为可能，这是以真空样品制备带来的限制为代价的。在过去的十年中，一个复杂的实验装置命名为电喷雾控制离子束沉积系统（ES-CIBD）的内部开发，最近已全面投入使用。利用这种仪器（国际上现有的少数仪器之一），我们可以将研究的分子系统类别扩展到大分子物种，这为吸附功能分子及其表面纳米级组装的化学和物理学开辟了以前无法进入的领域。为了使这一新的，非常有前途的研究方向的进一步发展，一个专用的和通用的表征工具，要求，即一个可变的温度扫描探针显微镜集成隧道和原子力（STM和AFM）测量模式。所要求的仪器的主要目的是能够提供优化的工作流程，用于获取（i）软着陆大分子的高分辨率地形图（ii）分子构象、环境和分子自组装的表征，（iii）以局部接触电位差或表面态密度为特征的电子地图，以及（iv）纳米机械性能的表征和分子操作方案的探索。这将通过结合扫描隧道和原子力显微镜来实现。此外，在可变温度下的数据采集能够捕获动态效应，确定纳米级组织的热稳定性以及表面反应和过程的活化屏障。在这方面，预计~ 100至400 K的操作温度制度将提供足够的多功能性来研究相关纳米级现象的动力学。重要的是，原子力显微镜的能力是决定性的探索（超）薄膜的大分子物种和研究ES-CIBD制备非导电基板上，这是经常的科学和技术的兴趣或相关性。

The research of the group focusses on molecular nanoscience and surface physics of interfaces. The controlled environment of ultra-high vacuum enables the application of highly accurate characterisation methods, which comes at the cost of limitations posed by vacuum sample preparation. Over the last decade, a sophisticated experimental set-up named electrospray controlled ion beam deposition system (ES-CIBD) was developed in-house, which became fully operational recently. With this instrument, one of a small number existing internationally, we could expand the class of molecular systems studied to macromolecular species, which opens previously inaccessible playgrounds in the chemistry and physics of adsorbed functional molecules and their nanoscale assemblies on surfaces. To enable the further development of this novel, highly promising research direction, a dedicated and versatile characterisation tool is requested, namely a variable temperature scanning probe microscope integrating both tunnelling and atomic force (STM and AFM) measurement modes. The main purpose of the requested instrumentation is to be able to provide an optimised work flow for acquisition of (i) high-resolution topographic maps of soft-landed macromolecules (ii) characterisation of the molecular conformation, environment and molecular self-assembly, (iii) electronic maps featuring local contact potential difference or surface density of states and (iv) characterisation of nanomechanical properties and exploration of molecular manipulation protocols. This will be achieved by a combined scanning tunnelling and atomic force microscope. Additionally, the data acquisition at variable temperatures enables to capture dynamic effects, determine the thermal stability of nanoscale organisations, and activation barriers of surface reactions and processes. In this respect, an operational temperature regime of ~ 100 to 400 K is expected to provide adequate versatility to investigate the dynamics of the relevant nanoscale phenomena. Importantly, the AFM capabilities are decisive to explore (ultra-)thin films of macromolecular species and study ES-CIBD preparations on nonconductive substrates, which are frequently of scientific and technological interest or relevance.