Molecular engineering of Y‐series acceptors for nonfullerene organic solar cells

Abstract

The power conversion efficiencies (PCEs) of single‐junction organic solar cells (OSCs) have surpassed 19%, owing to the emerging Y‐series nonfullerene acceptors (NFAs). Undoubtedly, the power and flexibility of chemical design has been a strong driver for this rapid efficiency improvement in the OSC field. Over the course of the past 3 years, a variety of modifications have been made to the structure of the Y6 acceptor, and a large number of Y‐series NFAs have been reported to further improve performance. Herein, we present our insights into the rationale behind the Y6 acceptor and discuss the design principles toward high‐performance Y‐series NFAs. It is clear that structural modifications through choice of heteroatom, soluble chains, π spacers, central cores, and end groups alter the material characteristics and properties, contributing to distinctive photovoltaic performance. Subsequently, we analyze various design strategies of Y‐series‐containing materials, including polymerized small‐molecule acceptors (PSMA), non‐fused‐ring acceptors (NFRA), and all‐fused‐ring acceptors (AFRA). This review is expected to be of value in providing effective molecular design strategies for high‐performance NFAs in future innovations.

Path to the fabrication of efficient, stable and commercially viable large-area organic solar cells

“…Based on this paper, studies have been actively conducted to make various modifications while retaining a basic Y-shapelike Y6 backbone. Representative studies related to the modifications of Y6 NFA include variation in the side chains at the thiophene beta-position as well as the inner pyrrole Natoms of the central core [38,39], end groups [40] and central core atoms [33,41] as shown in figure 3.…”

Isomerization strategy on a non-fullerene guest acceptor for stable organic solar cells with over 19% efficiency

“…20 Since then, numerous Y6-derivatives have been reported, rapidly pushing up the efficiency of OSCs. 21,22 Currently, the isomerization of Y6-derivatives has become an effective way to improve the performance of binary OSCs. [23][24][25] In particular, almost all the Y6-derivatives have been developed by employing isomeric endcapping groups or side chains, [26][27][28][29][30] but the isomerization of the central electron-deficient core in Y6-derivatives has never been investigated or reported.…”

N-type polymer semiconductors incorporating heteroannulated benzothiadiazole

“…Over the past few decades, organic semiconductors (OSCs) have attracted much attention for use in next-generation printed electronic devices because of their unique combination of mechanical flexibility and low weight, low potential fabrication costs, and synthetic tunability compared to traditional inorganic semiconductors. [1][2][3] These materials can be used in a wide range of applications, from organic photovoltaics (OPVs), [4][5][6] organic field-effect transistors (OFETs) 7,8 to organic light-emitting diodes (OLEDs) and beyond. 9 To realize the potential of these technologies, extensive efforts have been directed towards tuning the properties of OSCs, including their light-absorbing ability and charge carrier transport, primarily via the design and synthesis of novel semiconducting compounds.…”