Photoelectron Spectroscopy Measurements on Molecular Single Crystal Samples

Electronic processes at interfaces embedded in organic electronic devices are essential for their functionalities. Surface science researches, whose one predominant concept is the usage of single crystal surfaces of the materials as substrates for “well-defined” interfaces, have disclosed crucial insights into such interfaces. However, studies targeting the electronic states of organic molecular single crystal surfaces and well-defined interfaces formed on these are quite limited so far mainly due to some technical hurdles for the application of photoelectron spectroscopy measurements on bulk molecular solid-state samples. This article is devoted to outlining experimental requirements and know-how for applying photoelectron spectroscopy measurements to molecular single crystal samples, taking our recent research using microscopic X-ray photoelectron spectroscopy as examples.