New type solar cells using doped organic single crystal wafers

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22175
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 32:Physical chemistry, functional solid state chemistry, and related fields
• Research Institution: Institute for Molecular Science
• Principal Investigator: Hiramoto Masahiro 分子科学研究所, 物質分子科学研究領域, 教授 (20208854)
• Co-Investigator(Kenkyū-buntansha): 伊澤 誠一郎 分子科学研究所, 物質分子科学研究領域, 助教 (60779809)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 有機太陽電池 / ドーピング有機単結晶 / 長距離励起子拡散距離 / ルブレン単結晶 / バルクヘテロ接合 / ドナー／アクセプター接合 / 水平接合 / 無輻射再結合

Outline of Final Research Achievements

New-type of organic solar cells using p-doped rubrene single crystal wafers were successfully operated. Exciton collection efficiency reached 47% by utilizing very long exciton diffusion length of 2.7 micrometer in rubrene single crystals. On the other hand, new concept of “lateral junction”, in which the photogenerated carriers are extracted laterally to the substrate, the photovoltaic cell having the lateral junction of macroscopic length of 1.8 cm was successfully operated. Thus, we proposed the new architecture of organic solar cells free from “bulkheterojunction”.

Free Research Field

有機半導体の光電物性と有機太陽電池応用

Academic Significance and Societal Importance of the Research Achievements

有機太陽電池は、ドナー性とアクセプター性の有機半導体を混合するバルクヘテロ接合が主流となっているが、正負キャリアを電極に取り出すナノ構造制御の方法が未だ確立されていない。本研究の成果は、以上の問題を持つバルクヘテロ接合を不要にし、将来の有機太陽電池の新しい発展の道筋を提案するもので、学問的に非常に意義が大きい。