Junction properties and conduction mechanism of new terbium complexes with triethylene glycol ligand for potential application in organic electronic device

Terbium-picrate triethylene glycol（EO3-Tb-Pic） complex was prepared in thin film and single layer device structure of ITO/EO3-Tb-Pic/Al, using spin coating technique. The UV-Vis absorption spectroscopy analysis was performed to evaluate the electronic molecular transition of the complex. The optical band gap, Eg estimated from the Tauc model revealed that EO3-Tb-Pic thin film exhibited a direct transition with Eg of 2.70 eV. The electronic parameters of the ITO/EO3-Tb-Pic/Al device such as the ideality factor n, barrier height Φb, saturation current Io, and series resistance Rs, were extracted from the conventional lnI-V, Cheung＇s functions and Norde＇s method. It was found that the evaluated parameters calculated from Norde＇s and Cheung＇s methods were consistent with those calculated from the conventional I-V method. In the double logarithmic I-V plot, three distinct regions based on the slope were identified, and the conduction mechanisms were discussed and explained. The mobility, μ value was estimated from SCLC region as 2.58×10^–7 cm2/（V·s）. This newly obtained lanthanide complex may be potentially utilized in electronic devices.