Admittance spectroscopy and material modeling for organic electronic applications

Organic materials, both insulators and semiconductors, led to impressive applications in recent years and particular attention was paid to their performance reliability under realistic atmospheric conditions, fundamental need for the feasibility of organic electronic devices. In this context one of the most critical topics is the investigation of elements affecting device performance, such as trap states at the interface between different materials, and a fundamental target is to provide reliable physical models. By the means of admittance spectroscopy, in this paper, an electrical model was developed to explain the different dynamics of an organic device. Every element of the model was connected to each other through different relationships, each describing a single process. The model provides an efficient parameter extraction method, allowing for example the characterization of the diffusion of mobile ions, the dispersive transport in organic semiconductor bulk, the contact resistance at the metal-organic interface. As a consequence, the model is useful to compare the properties and the performance of devices with respect to the geometries, the materials and the fabrication process conditions