Recent Progress of Y6‐Derived Asymmetric Fused Ring Electron Acceptors

Abstract

Symmetric conjugated molecules can be broken through suitable synthetic strategies to construct novel asymmetric molecules, which can largely broaden the material library. In the field of organic solar cells, fused‐ring electron acceptors (FREAs) with the A‐DA'D‐A type backbone structure have attracted much attention and enabled power conversion efficiencies (PCE) exceeding 18%. Among them, Y6 is one of the most classic FREAs that can derive many symmetric and asymmetric molecules and exhibit unique optoelectronic properties. Thus, in this review, the focus is on the recent progress of Y6‐derived asymmetric FREAs containing a dipyrrolobenzothiadiazole segment, which can be classified as the following three categories: asymmetric end group, asymmetric central core and asymmetric side chain. The relationship of the molecular structure, optoelectronic properties, and device performance is discussed in detail. Finally, the future design directions and challenges faced by this kind of photovoltaic materials are given.

Side Chain Length and Interaction Mediated Charge Transport Networks of Non-Fullerene Acceptors for Efficient Organic Solar Cells

“…As an emerging renewable energy technology, organic solar cells (OSCs) have given rise to extensive attention owning to their advantages including lightweight, mechanical-flexibility, and solution-processing ability. − Over the past several years, the maximum power conversion efficiency (PCE) of OSCs has exhibited rapid growth, with a PCE of 11% in 2015 to over 20% in 2022. − This inspiring breakthrough can be attributed to the arise of new non-fullerene acceptors (NFAs) as well as physical control of their aggregation states that are optimal for power conversion. − …”

Organic Photovoltaic Cells Based on Nonhalogenated Polymer Donors and Nonhalogenated A-DA′D-A-Type Nonfullerene Acceptors with High VOC and Low Nonradiative Voltage Loss

“…With the emergence and continued development of A-DA′D-A-type Y-series nonfullerene acceptors (NFAs), − the power conversion efficiency (PCE) of single-junction binary organic photovoltaics (OPVs) has exceeded 18%. − Among the three photovoltaic parameters, both the short-circuit current density ( J SC ) and fill factor (FF) have made great progress, but the open-circuit voltage ( V OC ) is still limited to less than 1.0 V − for Y-series NFAs. The lower V OC is becoming a major limiting factor for OPVs to make further breakthroughs in performance.…”

Isomeric non-fullerene acceptors for high-efficiency organic solar cells

“…As one of the promising green energy technologies, organic solar cells (OSCs) have received tremendous attention due to their advantages of low cost, light weight, flexibility and roll-toroll manufacturing capability. [1][2][3][4][5][6][7][8][9][10][11][12][13] In the past few years, the power conversion efficiencies (PCEs) of OSCs have been frequently refreshed and have reached exciting values of over 19%. [14][15][16][17] These remarkable results are mainly attributed to the design of new and excellent active-layer materials, together with a deep understanding of the OSC mechanism and device optimization.…”