Non‐Fused Ring Acceptors Achieving over 15.6% Efficiency Organic Solar Cell by Long Exciton Diffusion Length of Alloy‐Like Phase and Vertical Phase Separation Induced by Hole Transport Layer

Abstract

of low cost, lightweight, flexibility, and semitransparency. With the development of new materials and the resulting underlying device physics, state-of-theart devices have achieved power conversion efficiencies (PCEs) exceeding 19% in single-junction OSCs based on nonfullerene acceptors. [1][2][3][4][5][6][7][8][9][10] Among highperformance OSCs, the combination of narrow bandgap fused-ring electron acceptors (FREAs) with a medium-bandgap polymer donor has become a popular approach for simultaneously realizing high photovoltaic parameters, including short-circuit current density (J sc ), fill factor (FF), and open-circuit voltage (V oc ). [11][12][13][14] In 2017, Bo et al. first reported the nonfused ring acceptor (NFERA), also called supramolecular fused ring acceptor, whose planar conformation can be locked by intramolecular noncovalent, and they achieved a decent PCE of 9.6%. [15] During the past several years, the NFREAs have attracted more and more attention as a potential alternative material to FREAs due to their easy synthesis, low synthesis complexity, low cost, and diverse molecular structures. [16][17][18][19][20][21][22] Although the development of NFREAs still falls behind that of FREAs, some NFREAs can achieve PCEs above

Additive engineering for high-performance P3HT:non-fused ring electron acceptor organic solar cell

“…7e, the 1-CN-processed film exhibits the surface energy between P3HT and MOT, indicating that the donor and acceptor can effectively diffuse into the other phase. 34 However, for the 1-MN- and 1-PN-processed blend films, the higher or lower surface energy indicates uneven distribution of donor and acceptor. Specially, the 1-MN processed blend film exhibit the higher surface energy for greater phase separation.…”

“…Recently, researchers have shifted their focus to newly developed non-fused ring electron acceptors (NFREAs) due to their easy synthesis, low cost, and diverse molecular structures. [22][23][24][25][26][27][28][29][30][31] Some of these NFREAs, including high-performance NFREAs developed in our lab, have demonstrated PCEs over 15%, 24,26,[32][33][34] making them potentially suitable for use with P3HT due to their tunable energy levels and energy bandgap. However, only few studies have investigated P3HT:NFREA blends due to their low PCE, and straightforward approaches to control phase separation in the blend film and optimize P3HT-based OSCs are rare.…”

Easily Available High‐Performance Organic Solar Cells by Regulating Phenylalkyl Side Groups of Non‐Fused Ring Electron Acceptors

“…[23][24][25][26] Encouragingly, OSCs based on NFREAs have surpassed 15% in some cases. [21,[27][28][29][30][31] Developing new molecular backbones of NFREAs, and paring with more efficient polymer donors to further boosts device efficiency could be expected. However, the expenditure in fabricating solar cells requires carefully considered in the future commercialization.…”

Progress and Future Potential of All-Small-Molecule Organic Solar Cells Based on the Benzodithiophene Donor Material

“…Solution-processed bulk-heterojunction (BHJ) organic solar cells (OSCs) have emerged as a potential contender for next-generation photovoltaic technology because of their advantages, such as low carbon footprint, low-temperature processing, short energy payback period, and facile manufacture into flexible, lightweight, and semitransparent products. Power conversion efficiencies (PCEs) have exceeded 19% in single-junction OSCs based on conjugated polymers as electron donor materials in recent years, thanks to the design of non-fullerene acceptors (NFAs) and device optimization [ 1 , 2 , 3 , 4 , 5 ]. Meanwhile, solution-processed small-molecule-based OSCs (SM-OSCs) are emerging as a competitive alternative to their polymer counterparts due to several important advantages of small molecules, such as well-defined structures and therefore less batch-to-batch variation, easier band structure control, etc.…”