Development of the artificial retina film based on light-harvesting antenna structure

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K22107
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 28:Nano/micro science and related fields
• Research Institution: Kyoto Institute of Technology
• Principal Investigator: Asaoka Sadayuki 京都工芸繊維大学, 材料化学系, 准教授 (50336525)
• Project Period (FY): 2019-06-28 – 2024-03-31
• Keywords: 光電変換 / 人工網膜 / 励起子移動 / フォトダイオードアレイ

Outline of Final Research Achievements

Aiming to create nano-photoelectric conversion arrays applicable to artificial retinas, the normally oriented cylindrical microphase-separated thin films, where pigment molecules are densely packed in the multilayered cyclic arrangement similar to those found in plant light-harvesting antennas, were fabricated. In addition to conventional porphyrins, various metal complexes coordinated with bipyridine ligands were successfully introduced into similar nanostructured thin films. By constructing multilayer films according to the energy gradient of the pigment molecules, the formation of down-conversion pathways was confirmed through enhanced photocurrent values. Furthermore, in thin films incorporating copper iodide as a charge carrier within the cylinders, an increase in surface charge density on the cylinder parts upon photoirradiation was observed, as verified by FM-KFM mapping of charges.

Free Research Field

有機合成化学

Academic Significance and Societal Importance of the Research Achievements

ブロック共重合体のミクロ相分離構造を利用することにより、従来報告されているAu-TiO2ナノワイヤを用いたナノサイズの光電変換素子よりも二桁高い集積度のナノ光電変換素子アレイを作成し、膜表面の各ドットが独立して光電流を生成することをFM-KFM法により実証した。現在市販されている装置では分解能が限界に近く、またシリンダー内部への電荷キャリアの導入が不均一であることから、一様な光電流応答を得ることはできなかったが、今後の測定装置の進歩と電荷キャリアの導入条件の最適化により、人工網膜やナノ光センサーへの適用も可能になるものと期待される。