Magnetoelectroluminescence and Magnetoconductance of Polymer Light-emitting Diodes by Using Ni-Fe Alloy Electrode

• Main Authors: Jing-YuanJhou, 周靖淵
• Other Authors: Ten-Chin Wen
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/96371680637409321663

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 100 === The main research in this paper is to explore the effect of spin-polarized injection in polymer light emitting diode by using ferromagnetic electrode. We indirectly observe spin-polarized carrier injection from the ferromagnetic electrode through the magnetoelectroluminescence and magnetoconductance measurement and the theoretical model. At first, we manufacture a light-emitting diode device by using G-PF(polyfluorene) to be emission layer, PEDOT:PSS and tetraoctylammnioum bromide(TOAB) as the hole transport layer and electron injection layer, then aluminum to be cathode. Furthermore, we analysis the electric field curve and magnetic field measurement data at high magnetic fields to figure out which component affect magnetic field effect, then discuss carrier behavior inside the device. In another way, we use Ni-Fe alloy as the electrode, and the carrier can be effectively polarized injected light-emitting layer and recombination, then we observe the increase of magnetoconductance ratio and the decrease of negative magnetic field effect of magnetoelectroluminescence. We observe some dependent relationship between the device with Ni-Fe alloy anode and the saturation magnetic field of the hysteresis curve of the Ni-Fe alloy, and the negative component of magnetoconductance. We thought the Ni-Fe alloy anode affect not only the spin polarized injection, but also the spin polarized collection. There is an oxide layer between anode and organic layer by using x-ray photoelectron spectroscopy measurement, and it cause antiferromagnetic coupling interaction result in negative magnetic field effect. Therefore, it is helpful to explain the mechanism of excited states from those experimental results, and provide confirmation of the excitation mechanism and the spin polarized injection mechanism.