AC Characterization of Hybrid Light-Emitting Devices: Electric Properties and Electroluminescence.

Abstract

The present project aims to study the electroluminescent process in EL devices based on inorganic electroluminescent material and conjugated polymer. Although EL phosphor materials, as the ELs devices made from these materials, have been widely studied since the 1950s, publications about the manufacture of the first device as we intend to study dating back to the 2000s. The continuous research involving inorganic EL materials for devices is mainly due to the high commercial appeal of these technologies, which survived decades of technological advances. In this sense, this project is dedicated to the comprehension of the operational physical mechanisms of this devices class. Specifically, we aim to understand the electronic carrier injection processes in EL hybrids, the charge transport processes though the hybrid composite volume, and to establish the relationship between these electrical mechanisms and the electroluminescence process. For both processes studies we intend to employ the impedance spectroscopy technique. The electroluminescence process characterization will be made by a quite similar procedure, where the alternating light intensity signal is compared to the alternating excitation signal (AC). These AC characterization techniques, electrical and of the electroluminescence, allow the observation of isolated mechanisms that have distinct dynamics, therefore the techniques allow to establish the relationship between the electroluminescence process with the injection and/or transport of electrical charges mechanisms.