[21p-W631-1~14] 12.2 Characterization and Materials Physics

▼ [21p-W631-10] Studying Magnetic Field Effect on Pentacene Field Effect Transistor Using Impedance Spectroscopy

〇SongToan Pham¹, Hirokazu Tada¹ (1.Graduate School of Engineering Science, Osaka University)

Keywords:Magnetoresistance,Impedance spectroscopy,Field effect transistor

Magnetic field effects observed in various organic devices, abbreviated as OME, are of great scientific interest because of their large magnetoresistance (MR) up to 10% at room temperature and under small magnetic fields of approximately 10 mT without ferromagnetic contacts [1]. Although debate still exists about its nature [2], these properties make OME devices desirable for magnetic field sensors, which may become an important component for future “plastic” electronics. Recently, the negative OME was observed in thin-film pentacene field effect transistors (FET) under the light irradiation [3]. However, the detail mechanism is still vague. In this work, OME in pentacene transistors was studied by impedance spectroscopy. The impedance data reveal that the origin of magnetic field effect on the photo-current may derive from the magnetic field dependence of recombination rate of photo-generated charges.