A double-cable Y-series-based polymer acceptor for efficient all-polymer solar cells: a new strategy of polymerizing small molecule acceptors

Abstract

Further advancement of all-polymer solar cells (all-PSCs) requires a new polymerization design strategy to develop ideal polymer acceptors that possess and retain maximally the advantages of narrow bandgap non-fullerene acceptor...

Non‐Fully Conjugated Photovoltaic Materials with Y‐Series Acceptor Backbone for High‐Performance Organic Solar Cells†

“…After that, they reported another non‐fully conjugated PSMA named PT‐BTP (Figure 3). [ 35 ] PT‐BTP with a double‐cable structure is composed of Y‐series SMA framework as a pendant side unit and thiophene derivative as the conjugated backbone, which possesses a narrow bandgap of 1.35 eV, high electron mobility, and favorable active layer morphology when blended with donor PM6. As a result, the PM6:PT‐BTP‐based all‐PSCs achieved a decent PCE of 12.13%.…”

“…Among the optimization of molecular backbone, π‐conjugated spacers are generally used as the linkers, including thiophene, [ 15 ] furan, [ 16 ] selenophene, [ 17 ] benzodithiophene, [ 18 ] etc ., to finely adjust intermolecular/intramolecular interactions of photovoltaic materials, thus achieving adjustable energy level, molecular packing, and charge transporting properties. Recently, different from the above π‐conjugated linkers, an emerging molecular design strategy with flexible alkyl units as linkers to construct non‐fully conjugated acceptors with Y‐series backbone has been developed, [ 19‐36 ] which provides a new channel to design high‐performance photovoltaic materials. Particularly, flexible alkyl linkers have advantages of being simple to synthesize, finely adjustable alkyl type and size, small steric hindrance, intrinsic stretchability, and extremely weak aromaticity.…”

High-performance binary all-polymer solar cells enabled by a Y-derivative pendant random-copolymerized polymer acceptor with a broad donor–acceptor matching tolerance

“…15,[28][29][30] Notably, the coupling between electron and vibration transitions is reduced due to the polymerization of SMAs, which can weaken the Coulomb interaction and is an effective way to reduce the exciton binding energy of NFSMAs, thereby resulting in a reduced voltage loss in devices. 31,32 In the past ve years, many efforts have been devoted to developing highperformance PSMAs by modulating p-conjugated fused-ring cores, 33 electron-decient end groups, 34 p-linkers, 35,36 halogen substitution, 37 and gra-structures 28,38 and matching with suitable P D s. [39][40][41][42] Consequently, the PCEs of all-PSCs have rapidly increased from 11% to approximately 18%, [42][43][44][45] which signicantly reduced the efficiency gap between P D :P A systems and P D :SMNFA systems. 46 The purpose of the above-mentioned efforts is not only to increase the J SC and open-circuit voltage (V OC ), but also improving the ll factor (FF), as prominently demonstrated in numerous works.…”