Wagner Thorsten, Antczak Grażyna, Ghanbari Ebrahim, Navarro-Quezada Andrea, Györök Michael, Volokitina Anna, Marschner Felix, Zeppenfeld Peter
Johannes Kepler University, Institute of Experimental Physics, Surface Science Division, Altenberger Str. 69, 4040 Linz, Austria.
University of Wrocław, Institute of Experimental Physics, Pl. M. Borna 9, 50-204 Wrocław, Poland.
Ultramicroscopy. 2022 Mar;233:113427. doi: 10.1016/j.ultramic.2021.113427. Epub 2021 Dec 11.
Photoelectron emission microscopy (PEEM) and low energy electron microscopy (LEEM) can easily distinguish between organic molecules adsorbed in crystallites or in the wetting layers as well as the bare metal substrate due to their different electronic properties. Already before (and during) the condensation of such solid phases (2D islands or 3D crystallites), there is a dilute 2D gas phase. Such a 2D gas phase consists of molecules, which are highly mobile and diffuse across the surface. The individual molecules are too small to be resolved in PEEM/LEEM images. Here, we discuss, how image features below and above the resolution limit of a PEEM/LEEM affect the mean electron yield and its (normalized) standard deviation. We support our findings with two experimental examples: the deposition of cobalt phthalocyanine (CoPc) on Ag(100) and of perfluoro-pentacene on Ag(110). Our results demonstrate, how a spatial and temporal analysis of image series can be used to obtain information about molecular phases, which cannot be directly resolved in microscopy images.
光电子发射显微镜（PEEM）和低能电子显微镜（LEEM）能够轻易地区分吸附在微晶或润湿层中的有机分子以及裸露的金属衬底，这是由于它们具有不同的电子特性。在这种固相（二维岛或三维微晶）凝聚之前（及过程中），就存在一种稀薄的二维气相。这种二维气相由高度可移动且能在表面扩散的分子组成。单个分子太小，无法在PEEM/LEEM图像中分辨出来。在此，我们讨论PEEM/LEEM分辨率极限上下的图像特征如何影响平均电子产额及其（归一化）标准偏差。我们通过两个实验示例来支持我们的发现：钴酞菁（CoPc）在Ag(100)上的沉积以及全氟并五苯在Ag(110)上的沉积。我们的结果表明，如何通过对图像序列进行空间和时间分析来获取关于分子相的信息，而这些信息在显微镜图像中无法直接分辨。
