Spatially Resolved Coherent Control of Exciton Diffusion Using Multiple Ultrashort Pulses

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01888
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Osaka University
• Principal Investigator: Sotome Hikaru 大阪大学, 大学院基礎工学研究科, 助教 (60758697)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 励起子拡散 / 時間分解分光 / 超解像イメージング / 太陽電池 / 有機EL / 超分子ポリマー

Outline of Final Research Achievements

We aim to develop a method for directly detecting and optically controlling exciton diffusion dynamics in optoelectronic materials such as solar cells and emissive devices. We constructed an ultrafast imaging setup equipped with multiple excitation pulses and applied to real-space observation of exciton diffusion. As a result, the diffusion behavior varies depending on the position inside samples and anisotropic diffusion was observed, which is reflected by spatial heterogeneity of the system. Furthermore, the exciton diffusion coefficients are dependent on the initial exciton density, thereby demonstrating that the diffusion behavior can be modulated by using the exciton-exciton annihilation process.

Free Research Field

物理化学

Academic Significance and Societal Importance of the Research Achievements

本研究で培った励起子拡散の可視化・制御技術は、コヒーレント制御という基礎科学的な見地からだけでなく、励起子の有効利用の観点で、太陽電池や発光材料といった光電変換材料における高効率化につながり、光エネルギー変換や光物質変換プロセスに資するものである。さらに、スピン状態のもつれを利用する量子情報科学など、新興の励起子関連科学にも波及するものである。