Non-fused Polymerized Small-Molecule Acceptors with a Benzothiadiazole Core for All-Polymer Solar Cells

Abstract

Polymerized small-molecule acceptors (PSMAs) have made significant progress as the application in all-polymer solar cells (all-PSCs). Most PSMAs are constructed by near-infrared fused-ring electron acceptors via Stille polymerization, such as Y-series acceptors. However, very limited non-fused electron acceptors with simplified synthetic complexity have been used in PSMAs. In this work, two non-fused PSMAs with a benzothiadiazole (BT) core are developed for application in all-PSCs. The S–O non-covalent interaction and the regioregularity have been introduced to improve the crystallinity and charge transport properties. As a result, a high-power conversion efficiency (PCE) of 11.42% with an enhanced photocurrent has been obtained in these regioregular PBTO-γ-based solar cells, representing the highest PCEs based on non-fused PSMAs. The encouraging results will intrigue more design of non-fused PSMAs toward high-performance all-PSCs.

Modulating the Central Units of Polymerized Nonfused Electron Acceptors for All-Polymer Solar Cells

“…In 2017, polymerized small-molecule acceptors (PSMAs) were applied to all-PSCs by Li’s group . This novel acceptor combines the advantages of small molecules and polymers, including high absorption coefficients with broad photoresponse, high electron mobilities, and well-aligned energy levels. , The flexibility in the structural design of PSMAs gradually clarified the structure–property relationships in all-PSCs. − Thanks to the high-performance module molecule Y6, the PCEs of all-PSCs based on PSMAs exceeded 17%. , However, molecules with fused-ring structures are generally more complex to synthesize, thereby increasing the synthesis cost. PSMAs based on nonfused-core structures have gradually gained attention because of their advantages of simple synthesis and considerable performance. − Nevertheless, most researches of nonfused-core-based PSMAs focus on the adjustment of the end groups and comonomers. ,,,− The influence of modulating the central units on the photophysical properties of nonfused-core-based PSMAs has not yet been studied.…”

“…25 This novel acceptor combines the advantages of small molecules and polymers, including high absorption coefficients with broad photoresponse, high electron mobilities, and well-aligned energy levels. 26,27 The flexibility in the structural design of PSMAs gradually clarified the structure−property relationships in all-PSCs. 28−38 Thanks to the high-performance module molecule Y6, the PCEs of all-PSCs based on PSMAs exceeded 17%.…”

Insight into the efficiency‐stability‐cost balanced organic solar cell based on a polymerized nonfused‐ring electron acceptor

“…Recently, we proposed a novel strategy of polymerized NFREA (PNFREA), [ 51 ] followed by various efforts from other groups, [ 52–56 ] exhibiting the potential of achieving low cost as well as excellent thermal/morphological stability. However, the PCEs of the PNFREAs usually lagged behind their NFREAs counterparts, which hinder their industrial viability.…”

“…[34][35][36][37][38][39][40] Due to the simple-structured conjugated backbone and the concise synthetic route, NFREAs are regarded as a promising candidate for efficiency-cost balanced OSCs. [41][42][43][44][45][46][47][48][49][50] Recently, we proposed a novel strategy of polymerized NFREA (PNFREA), [51] followed by various efforts from other groups, [52][53][54][55][56] exhibiting the potential of achieving low cost as well as excellent thermal/morphological stability. However, the PCEs of the PNFREAs usually lagged behind their NFREAs counterparts, which hinder their industrial viability.…”

Incorporating Naphthalene and Halogen into Near-Infrared Double-Cable Conjugated Polymers for Single-Component Organic Solar Cells with Low-Voltage Losses

“…Recently, remarkable advancements have been achieved in enhancing the power conversion efficiencies (PCEs) of organic solar cells (OSCs) through the invention of non-fullerene type acceptors with near-infrared (NIR) absorbing ability, resulting in efficiencies surpassing 19%. – Generally, the successful translation of laboratory research into commercial applications requires careful consideration of a tripartite balance encompassing cost-effectiveness, high PCEs, and prolonged stability. However, the durability of bulk-heterojunction (BHJ)-type OSCs over extended periods poses a substantial challenge to their widespread commercialization. , To address this challenge, the integration of double-cable type conjugated polymers, featuring covalently connected donor and acceptor fragments, has been explored in single-component OSCs (SCOSCs), which offer enhanced shelf stability, photostability, and thermostability. – Furthermore, SCOSCs exhibit simplified processing procedures, notable reduction in the costs associated with the fabrication processes, and photoactive layers. – Despite numerous advantages offered by SCOSCs grounded in double-cable conjugated polymers, their PCEs still lag behind those of BHJ-type OSCs due to the scarcity of suitable materials and the intricate nature of tuning the nanoscale separation morphologies within thin films. , …”