Antagonistic responses between magnetoconductance and magnetoelectroluminescence in polymer light-emitting diodes |
| |
Authors: | Kai-Wei Tsai Tsung-Hsun Lee Jin-Han Wu Jing-Yuan Jhou Wei-Shun Huang Sung-Nien Hsieh Ten-Chin Wen Tzung-Fang Guo JCA Huang |
| |
Affiliation: | 1. Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan;2. Institute of Electro-Optical Science and Engineering, National Cheng Kung University, Tainan, Taiwan;3. Department of Physics, National Cheng Kung University, Tainan, Taiwan;4. Advanced Optoelectronic Technology Center, National Cheng Kung University, 70101 Tainan, Taiwan |
| |
Abstract: | Antagonistic responses between magnetoconductance (MC) and magnetoelectroluminescence (MEL) in the polymer light-emitting diodes with an interfacial layer between Al cathode and active layer are simultaneously measured. As the interfacial layer (tetraoctylammonium bromide) is used, the significant increase in the number of injected negative polarons and the blocking of positive polarons promote the triplets-(free polaron) reaction and provide a good explanation for the reason that electroluminescence (EL) efficiency is maximal in the trap free space charge limited current regime at high bias. By fitting of MC and MEL curves using Lorentzian and non-Lorentzian empirical equations, three magnetic field dependent mechanisms, which are the intersystem crossing between singlet/triplet polaron pairs, the triplets-(free polaron) reaction, and the triplets-(trapped polaron) reaction are elucidated. The distribution of the three components is tunable by varying the applied electric field, which primarily modulates the triplets-(free polaron) reaction rate. The results pave a new route toward understanding the mechanism of organic spintronics for developing of multifunctional devices. |
| |
Keywords: | Interfacial layer Magnetoconductance Magnetoelectroluminescence Polymer light-emitting diodes |
本文献已被 ScienceDirect 等数据库收录! |
|