Graphdiyne Derivative as Multifunctional Solid Additive in Binary Organic Solar Cells with 17.3% Efficiency and High Reproductivity

Abstract

Morphology tuning of the blend film in organic solar cells (OSCs) is a key approach to improve device efficiencies. Among various strategies, solid additive is proposed as a simple and new way to enable morphology tuning. However, there exist few solid additives reported to meet such expectations. Herein, chlorine‐functionalized graphdiyne (GCl) is successfully applied as a multifunctional solid additive to fine‐tune the morphology and improve device efficiency as well as reproductivity for the first time. Compared with 15.6% efficiency for control devices, a record high efficiency of 17.3% with the certified one of 17.1% is obtained along with the simultaneous increase of short‐circuit current (Jsc) and fill factor (FF), displaying the state‐of‐the‐art binary organic solar cells at present. The redshift of the film absorption, enhanced crystallinity, prominent phase separation, improved mobility, and decreased charge recombination synergistically account for the increase of Jsc and FF after introducing GCl into the blend film. Moreover, the addition of GCl dramatically reduces batch‐to‐batch variations benefiting mass production owing to the nonvolatile property of GCl. All these results confirm the efficacy of GCl to enhance device performance, demonstrating a promising application of GCl as a multifunctional solid additive in the field of OSCs.

Understanding the Effect of End Group Halogenation in Tuning Miscibility and Morphology of High‐Performance Small Molecular Acceptors

“…[ 1–6 ] Nonfullerene small molecular acceptors (SMAs) [ 7–29 ] are the main driving force for the recent development of the field, with power conversion efficiencies (PCEs) over 17% reported by different teams. [ 30–43 ] SMAs have many attractive properties including their strong and tunable absorption, the easily adjustable energy levels and the enhanced chemical and device stability. Most of these excellent features are enabled by the flexible and feasible synthesis of the SMAs that leads to numerous judiciously designed molecular structures.…”

Highly Efficient All‐Small‐Molecule Organic Solar Cells with Appropriate Active Layer Morphology by Side Chain Engineering of Donor Molecules and Thermal Annealing

“…[ 1–4 ] The photovoltaic performance of organic solar cells (OSCs) has achieved tremendous improvement during the past two decades, benefitted from the innovation of novel OS materials and device technologies. [ 5–12 ] Small‐molecule OS materials, compared with polymer OS material, possess the distinct advantages of well‐defined chemical structure, easy purification, and better repeatability. [ 13–17 ] However, the power conversion efficiency (PCE) of the all small‐molecule SM‐OSCs (SM‐OSCs) with small molecule donor and small molecule acceptor always lags behind that of polymer solar cells (PSCs) with conjugated polymer donor and small molecule acceptor in the whole process of OSCs development.…”

Biomimetic Electrodes for Flexible Organic Solar Cells with Efficiencies over 16%

“…[ 1–4 ] A rapid progress in the development of OSCs has been achieved through new material syntheses, interfacial modifications, and architecture engineering. [ 5–15 ] A very high power conversion efficiency (PCE) exceeding 17% has recently been realized. [ 6,16–18 ] Nevertheless, the performances of flexible OSCs are still lagging behind those of conventional indium tin oxide (ITO)‐based rigid devices owing to the limits of flexible transparent electrodes (FTEs).…”

“…[ 5–15 ] A very high power conversion efficiency (PCE) exceeding 17% has recently been realized. [ 6,16–18 ] Nevertheless, the performances of flexible OSCs are still lagging behind those of conventional indium tin oxide (ITO)‐based rigid devices owing to the limits of flexible transparent electrodes (FTEs). [ 19–28 ] To realize the full potential of the flexible OSCs for emerging electronic devices requiring a good conformability and even expandability, extensive studies are required to develop better FTEs with combined superior optical transparency, electrical conductivity, mechanical bendability, and scalability.…”