Realization of spin transistor using organic single crystal semiconductor

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H06200
• Research Category: Grant-in-Aid for Challenging Research (Pioneering)
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Takeya Junichi 東京大学, 大学院新領域創成科学研究科, 教授 (20371289)
• Co-Investigator(Kenkyū-buntansha): 渡邉 峻一郎 東京大学, 大学院新領域創成科学研究科, 特任准教授 (40716718)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: 有機半導体 / 単結晶 / メカノエレクトロニクス / 分子振動 / スピントロニクス

Outline of Final Research Achievements

Practicing this research project has led to a great understanding of electron charge / spin transport in semiconductors. We have reported for the first time in the world that it is important to incorporate the effect of soft phonons into the standard theory of electron transport used in inorganic semiconductors. Furthermore, we conduct experimental research on spin transport by measuring field-effect characteristics at room temperature, measuring electronic properties in magnetic fields and at low temperatures, and electron spin resonance experiments, etc., and it was shown that the organic semiconductor can achieve both high mobility and long spin relaxation time of 1 millisecond or more. As a result of these achievements, we have obtained progress in physical property research more than originally planned, such as realization of very long spin relaxation time of organic semiconductor and metallic state of organic semiconductor at low temperature.

Free Research Field

有機半導体

Academic Significance and Societal Importance of the Research Achievements

本研究期間中には、有機半導体における電子電荷・スピン輸送において大きく理解が進展し、特に無機半導体で用いられている電子輸送の標準理論に柔らかいフォノンの効果を取り入れることが重要であることを世界に先駆けて報告した。また、非常に長いスピン緩和時間や低温での金属状態の実現など、当初の計画以上の物性研究の進展が得られた。単結晶デバイスを用いて初めて正確な構造物性相関を解明し、ホール効果などの精密物性測定による電子状態の詳細な理解と構造への対比が可能となったことは、信頼できる学問分野の構築に道を拓いたと言える。