Measuring frontier orbital energy levels of OLED materials using cyclic voltammetry in solution

• DOI: 10.1016/j.orgel.2023.106888
• Publication Date: 2023-07-01T00:53:28Z
• Authors: Gabriela P. Kissling; Beat Ruhstaller; Kurt P. Pernstich
• Keywords: HOMO/LUMO; Organic semiconductor

The operation of organic light emitting diodes (OLEDs) is governed by a range material parameters, such as frontier orbital energy levels, charge carrier mobility and excitonic rate parameters. In state-of-the art numerical simulations OLED devices, more than 30 parameters must be considered to describe the behavior multilayer device. Independent measurement techniques reliably determine each parameter individually are therefore highly desirable. While several have been established in community some them, highest occupied lowest unoccupied molecular (HOMO LUMO) levels not measured or reported on regular basis, despite their significant influence device performance. this work, we show how cyclic voltammetry solution can used simple technique measure HOMO LUMO semiconductors. This easily performed experiment allows fairly accurate estimation layers stack. Cyclic measurements four typical materials presented analysis described detail encourage future studies. Four distinctly different voltammograms were obtained, ranging from relatively ideal reversible very non-ideal behavior, lacking electrochemical reverse reactions. Two methods for extracting discussed compared. compare well with values thin films, showing that provides viable means important, yet underinvestigated property.