Developments and Applications of Nonlinear Photoresponsive Photochromic Materials

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K14194
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 32020:Functional solid state chemistry-related
• Research Institution: Ritsumeikan University
• Principal Investigator: KOBAYASHI Yoichi 立命館大学, 生命科学部, 准教授 (10722796)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: フォトクロミズム / 電子移動 / 非線形 / 段階的二光子 / 高励起状態 / 電荷分離状態

Outline of Final Research Achievements

Intensity dependent photochromic properties are not only important for fundamental interests, but also for various industrial applications such as holographic displays, photolithography, and super-resolution microscopy. In this project, we demonstrated the stepwise-two-photon induced electron transfer from the higher excited states of noncovalently bound protoporphyrin IX to colloidal CdS nanocrystals. Furthermore, we found that a photochromic rhodamine derivative shows stepwise two-photon induced photochromic reaction under relatively low excitation intensity. Stepwise two-photon induced photochromic reactions and electron transfers are important for developing further advanced photofunctional materials.

Free Research Field

機能物性化学

Academic Significance and Societal Importance of the Research Achievements

段階的二光子吸収過程は様々な非線形光学特性の中でも光強度閾値が極めて低く、パルスレーザーを用いなくとも誘起できる特徴がある。段階的二光子吸収過程を組み合わせた電子移動反応やフォトクロミック反応は、弱い背景光には応答せず、照射した光源の光にのみ特徴的に反応が進行するといった新しい光機能特性をもつ材料が期待される。また、光強度閾値の比較的低い非線形フォトクロミック材料は、次世代立体映像技術として期待される動画ホログラフィーの回折効率を向上し、フォトリソグラフィーや超解像顕微鏡などの空間分解能をさらに高める画期的な特性を発現できると期待される。