2023 Fiscal Year Final Research Report
Observation of conduction band structure of organic semiconductor and study of electron-phonon coupling
| Project/Area Number |
21H01902
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 32020:Functional solid state chemistry-related
|
|---|
| Research Institution | Chiba University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2021-04-01 – 2024-03-31
|
| Keywords | エネルギーバンド構造 / 角度分解低エネルギー逆光電子分光 / 電子－フォノン相互作用 / 部分ポーラロン / 電子輸送 / 移動度 |
|---|
| Outline of Final Research Achievements |
Organic semiconductors are considered to be next-generation semiconductors with unique properties such as lightness and flexibility. In semiconductors, charge carriers (holes and electrons) move around and generate their functionality. The most fundamental information for understanding the behavior of these charge carriers is the energy band structure (the dispersion relationship between energy and momentum).
The structure of the valence band responsible for hole transport has been reported since the 1990s. Conversely, the structure of the conduction band related to electron transport has not even been investigated experimentally. In this study, we have established low-energy angle-resolved inverted photoelectron spectroscopy, which allows us to observe the conduction band structure of organic semiconductors for the first time. This is an important step towards elucidating the electronic conduction mechanism of organic semiconductors.
|
| Free Research Field |
有機半導体
|
| Academic Significance and Societal Importance of the Research Achievements |
有機半導体の伝導帯バンド構造の測定方法を確立し、これを基に実験的な証拠がなかった高移動度有機半導体で準粒子ポーラロンが生成していることを初めて実証した。さらに新たな理論「部分ポーラロン」モデルを提案した。
有機半導体では、正孔に比べ電子の移動度が低いことが知られているが、原因は明らかでない。代表的な有機半導体であるペンタセンについて、実験・理論による解析により電子－フォノン相互作用がその起源であることを明らかにした。この結果は、これまで不明であった有機半導体の電子輸送機構の解明に先鞭をつけ、高性能ｎ型（電子輸送型）有機半導体の開発への道筋をつける。
|
