Development of Multipodal Hole-Transporting Monolayer Materials for High Performance Perovskite Solar Cells

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14744
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Kyoto University
• Principal Investigator: TRUONG MINHANH 京都大学, 化学研究所, 助教 (40792718)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: ペロブスカイト太陽電池 / マルチポッド型 / 電荷回収層 / 変換効率 / 単分子膜 / 化学吸着 / トリアザトリキセン / シクロオクタテトラインドール

Outline of Final Research Achievements

Hole-collecting monolayers have significantly advanced the performance of inverted perovskite solar cells. However, to date, all of the reported monolayer materials have only one anchoring group, align edge-on to the adjacent substrate, and show low wettability. In this work, we developed face-on oriented multipodal monolayer materials based on triazatruxene derivatives bearing multiple phosphonic acid anchoring groups. The face-on oriented tripodal material was found to facilitate hole extraction, leading to perovskite solar cells with enhanced stability and high power conversion efficiencies up to 23.0%. In addition, to improve the surface wettability of the monolayer, we also developed tetrapodal molecules by introducing four phosphonic anchoring groups into a saddle-like cyclooctatetraene skeleton. We found that the tetrapodal molecules can adsorb on the electrode surface with some phosphonic groups pointing upward, leading to a hydrophilic surface and improved wettability.

Free Research Field

有機化学、材料科学

Academic Significance and Societal Importance of the Research Achievements

ペロブスカイト太陽電池の分野において，これまでにほとんどの正孔回収材料がバルクの厚膜層として用いられてきた．しかし，正孔回収材料自体の厚膜による光吸収が取り出せる電流密度を低下させてしまい，又、この厚膜のモルフォロジーの安定性がデバイス自体の低い熱安定性の原因となっている．これに対して，本研究ではマルチポッド型構造をもつ単分子膜材料の配向配列制御による各層の界面の精密制御を実証し，太陽電池の高効率化・高耐久性化を達成した．マルチポッド型の有用性を実証することにより，本太陽電池の開発分野に多大なインパクトをもたらすとともに，その実用化を大きく加速できるものと期待できる．