Development of novel spin-probe techniques for organic devices by ESR-induced currents

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H03135
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Device related chemistry
• Research Institution: Osaka City University
• Principal Investigator: Kanemoto Katsuichi 大阪市立大学, 大学院理学研究科, 准教授 (40336756)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: EDMR / ODMR / 有機デバイス / ESR

Outline of Final Research Achievements

In this study, we developed techniques to utilize the current change that occurs when the electron spin is reversed in organic semiconductor devices. We found that the current change in OLEDs is caused by the spin reversal of electron-hole pairs. The electron-hole pairs were found to decrease with increasing voltage, and the EL process was classified into three regions depending on the voltage: the pair accumulation region, the pair dissociation/recombination region, and the non-pair formation region. It was also found that the nature of the electron-hole pairs determines the magnetic field responsivity of the OLEDs. We also investigated the electromotive force generated by ferromagnetic resonance in metal bilayer thin films, and clarified the relationship between the excitation power and the electromotive force due to the resonance.

Free Research Field

物性物理学

Academic Significance and Societal Importance of the Research Achievements

有機物質を代表とする半導体や導体には電子スピンをもつキャリヤやその複合体が存在しているが、そのスピンを磁気共鳴操作を用いて反転した際に素子にどのような影響が生じるか調べることは、新しいデバイスへの応用やデバイス内の物性を調べる手段を模索する意味で重要である。この研究ではその技術開拓を行うことを主眼とし、研究を行った結果、電子スピンの反転による電流変化を与える電子状態の起源を明らかにでき、さらには新たなスピン物性の開拓及び応用展開を行える手掛かりを得ることができた.