Tailoring Cyano Substitutions on Quinoxaline‐based Small‐Molecule Acceptors Enabling Enhanced Molecular Packing for High‐Performance Organic Solar Cells

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: 14(30)

Published: May 11, 2024

Abstract Cyanation is a common chemical modification strategy to fine‐tune the energy levels and molecular packing of organic semiconductors, especially materials used in solar cells (OSCs). Generally, cyanation modify end groups high‐performance small‐molecule acceptors (SMAs). However, has not been investigated on central backbone SMAs, which could introduce stronger intermolecular interaction enhance π–π stacking for rapid charge transport. This paper, first time, reports new benzo‐quinoxaline core synthesizes two novel A‐DA'D‐A type named BQx‐CN BQx‐2CN, with mono‐ di‐cyanide groups, respectively. Through tailoring number CN BQx‐CN‐based OSC exhibits best device performance 18.8%, significantly higher than non‐cyano BQx‐based one. The reason superior devices can be attributed fine‐tuned level, packing, ideal phase segregation, lead exciton dissociation, faster transport, suppressed recombination, therefore highest fill factor (FF) power conversion efficiencies (PCE). research demonstrates effectiveness SMAs enhanced better OSCs.

Language: Английский

---

Improving the Stability of Organic Solar Cells: From Materials to Devices

Solar RRL, Journal Year: 2023, Volume and Issue: 7(20)

Published: Aug. 24, 2023

Organic solar cells (OSCs) are a promising emerging photovoltaic technology for energy conversion. Recently, the power conversion efficiencies of OSCs have been improved to get closer their Schottky–Queisser limit. However, operational stability remains as major challenge ahead deployment practical applications. The main causes OSC instability stem from poor intrinsic materials, metastable morphology multicomponent active layer, unstable interfaces, and sensitivity moisture oxygen. To address these issues, it is necessary comprehensive in‐depth understanding fundamentals develop an integrated solution overcome them. Herein, state‐of‐art strategies used improve aspects material design, device processing, encapsulation techniques, in hope delivering rational solutions, summarized. In end, prospects toward future development efficient stable provided.

Language: Английский

---

Unraveling the Structure–Property–Performance Relationships of Fused-Ring Nonfullerene Acceptors: Toward a C-Shaped ortho-Benzodipyrrole-Based Acceptor for Highly Efficient Organic Photovoltaics

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 146(1), P. 833 - 848

Published: Dec. 19, 2023

The high-performance Y6-based nonfullerene acceptors (NFAs) feature a C-shaped A-DA'D-A-type molecular architecture with central electron-deficient thiadiazole (Tz) A' unit. In this work, we designed and synthesized new A-D-A-type NFA, termed CB16, having ortho-benzodipyrrole-based skeleton of Y6 but the Tz unit eliminated. When processed nonhalogenated xylene without using any additives, binary PM6:CB16 devices display remarkable power conversion efficiency (PCE) 18.32% high open-circuit voltage (Voc) 0.92 V, surpassing performance corresponding devices. contrast, similarly SB16, featuring an S-shaped para-benzodipyrrole-based skeleton, yields low PCE 0.15% due to strong side-chain aggregation SB16. A-DNBND-A in CB16 Y6-series NFAs constitutes essential structural foundation for achieving exceptional device performance. moiety or other units can be employed finely adjust intermolecular interactions. single-crystal X-ray structure reveals that ortho-benzodipyrrole-embedded plays important role formation 3D elliptical network packing efficient charge transport. Solution structures PM6:NFAs detected by small- wide-angle scattering (SWAXS) indicate removing could reduce self-packing thereby enhancing complexing networking PM6 spin-coating solution subsequent film. Elucidating structure–property–performance relationships work paves way future development structurally simplified NFAs.

Language: Английский

---

Facile, Versatile and Stepwise Synthesis of High‐Performance Oligomer Acceptors for Stable Organic Solar Cells

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(40)

Published: Aug. 8, 2023

Oligomer acceptors have recently emerged as promising photovoltaic materials for achieving high power conversion efficiency (PCE) and long-term stability in organic solar cells (OSCs). However, the limited availability of diverse acceptors, resulting from sole synthetic approach, has hindered their potential future industrialization. In this study, we present a facile effective stepwise approach that utilizes two consecutive Stille coupling reactions synthesis oligomer acceptors. To demonstrate feasibility novel successfully synthesize trimer acceptor, Tri-Y6-OD, further systematically investigate impact oligomerization on device performance stability. The results reveal significant advantages compared to conventional method, including reduced formation unwanted by-products lower difficulties purification. Remarkably, OSC based PM6 : Tri-Y6-OD achieves an impressive PCE 18.03 % maintains 80 initial (T80 ) 1523 h under illumination, surpassing corresponding small molecule acceptor Y6-OD-based device. Furthermore, versatility strategy obtaining is demonstrated. Overall, our findings provide facile, versatile way synthesizing thereby facilitating development stable efficient OSCs.

Language: Английский

---

Dimerized small molecular acceptors: Regulation of dimer conformation realizes binary organic solar cells with highly comprehensive performance

Nano Energy, Journal Year: 2023, Volume and Issue: 121, P. 109218 - 109218

Published: Dec. 20, 2023

Language: Английский

---