|Autors: Aleksandrova, M. P.|
Title: Investigation of the Defects Formation in Flexible Organic Light Emitting Devices by Thermal Activated Currents
Keywords: Organic light emitting devices, Thin films, Defects investigation, Thermal activated current
Abstract: Electrical behaviour of flexible light emitting devices at different temperatures was investigated. Organic electroluminescent layers were produced by different deposition methods – thermal evaporation in vacuum and spray coating. Thermally activated currents of the structures were measured in the range from 0 to 70 oC and the defect’s origin, and activation energy were determined and compared for both cases. It was established that the thermal activated current for thermal evaporated films was higher (~900 nA) than for spray deposited (~430 nA) and consists of several distinctive peaks. Therefore higher defect density, embracing broad energy spectrum are typically revealed for the evaporation process and can be ascribed to structural films deformations. Just the opposite for the pulverization process there is only slight change in the current-temperature characteristic (~1nA/oC), which is evidence for lack of structural deep traps and presence of impurity defects or shallow traps.
Вид: публикация в международен форум, публикация в реферирано издание