Fundamental characteristics of magnetic organic semiconductor thin film

• Main Authors: Tsung-JingWu, 吳宗璟
• Other Authors: Wei-Yang Chou
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/49474823162708236259

碩士 === 國立成功大學 === 光電科學與工程學系 === 102 === A magnetic organic semiconductor thin film composed of pentacene molecules and nickel (Ni) atoms that were co-deposited via molecular beam epitaxy was fabricated and studied. The physical properties of the intermolecular electron coupling between the 2p orbit of pentacene molecules and the 3d orbit of Ni atoms were examined via Raman mapping spectroscopy. The red-shift level of the peak at 1178 cm−1 increased with Ni doping and external magnetic field. Furthermore, the ratio of the peak intensity at 1178 cm−1 over that at 1371 cm−1 decreased with Ni doping and external magnetic field. Based on the change in Raman signal, an increment in intermolecular electron coupling was found with the overlap of the 2p orbit of pentacene molecules and the 3d orbit of Ni atoms. In addition, intermolecular electron coupling could be enhanced by external magnetic field. The distribution of Ni atoms was also studied via atomic force microscopy and conductive atomic force microscopy techniques. A comparison between pristine pentacene film and Ni-doped pentacene film showed that the current of grain boundary increased with Ni doping, which indicated that excess Ni atoms were deposited in the grain boundary. Finally, a model of magnetic transition called “magnetic transmission bridge” was proposed and used to explain the remanent magnetization of magnetic organic semiconductor thin films observed at room temperature.