20.6% Efficiency Organic Solar Cells Enabled by Incorporating a Lower Bandgap Guest Nonfullerene Acceptor Without Open‐Circuit Voltage Loss

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 28, 2025

Abstract Simultaneously mitigating both photovoltage and photocurrent losses is crucial for organic solar cells (OSCs) to approach the Shockley–Queisser limit of ideal efficiency. Incorporating a narrower bandgap nonfullerene acceptor (NFA) as guest component into host donor:NFA system broadens absorption spectrum. However, this can also increase nonradiative decay rate according energy‐gap law. In work, ternary OSCs are constructed by combining narrow AQx‐2F (as NFA) with lower eC9 NFA), significantly enhancing generation without compromising photovoltage. The addition acts crystallization inducer, extending period increasing ordered packing distance. This leads suppressed trap states, elevated dielectric constant, prolonged exciton lifetime, balanced hole/electron transport, reduced recombination loss. Consequently, optimized D18:AQx‐2F:eC9 achieve champion power conversion efficiency (PCE) 20.6% high open‐circuit voltage 0.937 V, short‐circuit current density 27.2 mA cm −2 fill factor 80.8%, validated an independently certified PCE 20.0%, establishing new benchmark bulk heterojunction OSCs. work demonstrates effective method simultaneously mitigate losses, paving way high‐performance

Language: Английский

---

Effect of the Number of Phenylcarbazole Units Adorned to the Silicon Atom for High Triplet Energy with High Charge Mobility

Molecules, Journal Year: 2025, Volume and Issue: 30(3), P. 454 - 454

Published: Jan. 21, 2025

Increasing the number of phenylcarbazole (PC) units attached to silicon atom in organic solid-state thin films led a remarkable enhancement charge mobility. Specifically, mobility values exhibited an increase from 1.32 × 10−4 cm2/Vs for 3PCBP 4.39 10–4 2MCBP, ultimately reaching 1.16 10–3 MCBP. Notably, these enhancements were achieved while maintaining high triplet energy 3.01 eV. DFT calculations on spin density distribution provided insights into nature improved preserving energy. The accuracy was validated by comparing results with experimental data photoemission spectroscopy (PES). Mobility measurements, as contemplated DFT, allowed comprehensive understanding factors influencing enhanced keeping constant. This study suggested that intramolecular transfers played crucial role reducing reorganization energy, showing inverse dependence PCs. Consequently, it inferred manipulation PC could effectively optimize transfer mechanisms, offering promising avenue tailoring electronic properties.

Language: Английский

---

Boosting The Solid‐State Luminescence of Phenazine Derivatives by Enhancing Intermolecular Hydrogen Bonds and π–π Interactions in Cocrystals

Chemistry - An Asian Journal, Journal Year: 2025, Volume and Issue: unknown

Published: April 14, 2025

Abstract Six monosubstituted phenazine derivatives were designed and synthesized for constructing cocrystals to investigate their structure–property relationship. It was found that 2‐substituted phenazines could form with 2,6‐dimethylphenylboronic acid (DBA). These exhibited red‐shifted enhanced luminescence relative individual components, especially 2NP‐DBA whose efficiency nearly 100 times higher than of 2NP. By analyzing the single‐crystal structures hydrogen bonds π–π interactions between molecules detected in cocrystals, which suppressed nonradiative transition pathways. Consequently, all three demonstrated strong continuous interactions, differed from previously reported enhancement resulting destruction interactions. An in‐depth investigation these can not only provide a better understanding structure‐property relationship organic luminescent materials, but also help develop materials intense solid‐state In addition, optical response acidic vapors has been successfully applied anti‐counterfeiting.

Language: Английский

---

Crystal Form Diversity of 2-(4-(Diphenylamino)benzylidene) Malononitrile

Crystals, Journal Year: 2025, Volume and Issue: 15(4), P. 380 - 380

Published: April 21, 2025

In the present work, we report synthesis and characterization of 2-(4-(diphenylamino)benzylidene) malononitrile (DPAM) via a piperidine-catalyzed Knoevenagel condensation reaction. Two distinct crystal forms (A-1 A-2) this product were obtained by controlling crystallization conditions, exhibiting orthorhombic monoclinic systems, respectively. Single-crystal X-ray diffraction revealed that both exhibited highly twisted benzene rings, which suppressed exciplex or excimer formation, enhancing luminescence. Crystal A-1, with higher density, showed stronger hydrogen bonding more rigid molecular packing, while A-2, lower weaker π–π interactions. Both crystals demonstrated high thermal stability. Notably, A-2 displayed mechanochromic behavior: grinding applying pressure induced structural transformation into accompanied fluorescence shift from red to yellow. This was attributed increased steric hindrance changes in packing. study highlights relationship between structure optoelectronic properties, offering insights design organic crystalline materials for applications sensing, anti-counterfeiting, information encryption.

Language: Английский

---