Effects of exciplex on the electroluminescent and photovoltaic properties of organic diodes based on terbium complex
Document Type
Article
Publication Date
1-1-2008
Abstract
We fabricated two organic diodes, one of which consists of a double layer structure of TPD/Tb(ACA)3phen and in the other one a mixture layer is inserted between the double layer, i.e., TPD/TPD:Tb(ACA)3phen (1:1, 30 nm)/Tb(ACA)3phen, here TPD and Tb(ACA)3phen are (N,N′-diphenyl-N,N′-bis(3-methyl-phenyl)-1,1′-biphenyl-4,4′-diamine) and tris(acetylacetonato)-(mono-phenothroline) terbium, respectively. Both the devices show electroluminescence (EL) properties under forward bias and photovoltaic (PV) effects under illumination of ultraviolet (UV) light. For the device with a mixture layer, the EL performance and PV effects were both significantly improved. A maximum EL brightness of 150 cd/m2 under bias of 17 V and a maximum efficiency of 1.1 cd/A at 7.5 V were obtained. Moreover, the diode shows a short-circuit current (Isc) of 43 μA cm-2, an open-circuit voltage (Voc) of 1.1 V, a fill factor (FF) of 0.32, and an overall power conversion efficiency (ηPV) of 1.0% under illumination of 365 nm UV light with 1.5 mW/cm2. The improvements of PV- and EL-properties were presumably attributed to the increased intermolecular contacts in the mixture of TPD and Tb-complex. In addition, a shift of EL color from UV-blue to green-yellow was also observed when a mixture layer of TPD with Tb-complex was inserted. The operation mechanisms of the EL- and the PV-processes of the diodes with different structures were further discussed. © 2007 Elsevier Ltd. All rights reserved.
Publication Source (Journal or Book title)
Solid-State Electronics
First Page
31
Last Page
36
Recommended Citation
He, H., Li, W., Su, Z., Li, T., Su, W., Chu, B., Bi, D., Han, L., Wang, D., Chen, L., Li, B., Zhang, Z., & Hu, Z. (2008). Effects of exciplex on the electroluminescent and photovoltaic properties of organic diodes based on terbium complex. Solid-State Electronics, 52 (1), 31-36. https://doi.org/10.1016/j.sse.2007.06.011