Analysis of Complete Organic Semiconductor Devices by Laser Desorption/Ionization Time‐of‐Flight Mass Spectrometry

Abstract In this contribution, it is shown that the method of laser‐desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF‐MS) is a powerful technique for analyzing complete organic devices, such as organic light‐emitting diodes (OLEDs) or organic solar cells. LDI‐TOF‐MS has the potential to analyze fully processed organic devices without special pretreatment such as dissolving the device, peeling off the metal cathode, or using additional matrix materials. Thus, devices may be analysed as they are with a minimum of measurement artefacts. It is demonstrated that the method allows an analysis of complex organic multilayer devices, their composition, and incorporated impurities. It even allows possible electrochemical reaction products caused by device degradation to be analyzed. Thus, LDI‐TOF‐MS has major advantages compared to measurements of dissolved samples. As an example, the identification of all of the materials used in a complete OLED is shown. Furthermore, a detailed chemical analysis of long‐term driven OLEDs, including the detection of degradation products, is presented. From these data, several degradation mechanisms can be distinguished.