(Invited) Development of Non-Fused Nonfullerene Acceptors Bearing Spiro-Substituted Structures and Application to Green-Light Wavelength-Selective Organic Solar Cells

Abstract

Organic solar cells (OSCs) have been extensively investigated as next-generation energy sources due to their potential for large-area fabrication, light weight, flexibility. The active layer of OSCs is composed of a blend of donors and acceptors, which form bulk heterojunction structures in the films. The development of A-D-A-type nonfullerene acceptors (NFAs) with large fused-ring donor structures have significantly accelerated OSC research. On the other hand, non-fused electron-accepting p-conjugated compounds have been investigated recently for application to NFAs. In this presentation, we focus on cyclopentene-annelated thiophene with spiro-substituted 2,7-bis(2-ethylhexyl)fluorene (FT) as a rigid and sterically bulky linker unit and develop a non-fused NFA containing FT units. We also focus on the development spiro-substituted NFAs with green-light wavelength-selective absorbance. The combination of these acceptors and poly(3-hexylthiophene) can produce green-light wavelength-selective OSCs for application in new greenhouse agrivoltaics.