Han Jianhua, Xu Han, Sharma Anirudh, Asatryan Jesika, Rauch Florian, Friedrich Alexandra, Krebs Johannes, Swoboda Lukas, Schuster Julia, Pagidi Sudhakar, Kalluvettukuzhy Neena K, Alqurashi Maryam, Thilagar Pakkirisamy, Schopper Nils, Krummenacher Ivo, Stepanenko Vladimir, Finze Maik, Braunschweig Holger, Martín Jaime, Würthner Frank, Baran Derya, Marder Todd B
Julius-Maximilians-Universität Würzburg, Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Am Hubland, Würzburg 97074, Germany.
Materials Science and Engineering Program (MSE), Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
J Am Chem Soc. 2025 Aug 13;147(32):28694-28713. doi: 10.1021/jacs.5c02308. Epub 2025 Aug 4.
The triarylborane family has expanded rapidly as valuable π electron-accepting moieties in organic materials, yet the performance and application of triarylboranes in organic photovoltaics (OPVs) have thus far been limited. Herein, we present a comprehensive platform of 17 distinct triarylboranes to investigate their structure-property relationships from single crystals to heterojunction blends and further to OPV device performance. We show that twisted triarylboranes exhibit distinct molecular packing behavior in the solid state, characterized by limited π-π stacking and the lack of the face-on orientation required for efficient light-to-electric conversion, in contrast to state-of-the-art OPV materials. However, when incorporated as a third component, triarylboranes induce red-shifted absorption and blue-shifted photoluminescence spectra in OPV materials, thereby reducing reorganization energies in blends. Furthermore, triarylboranes possessing high dipole moments and trap-free energetics enhance power conversion efficiencies (PCEs) in devices. Notably, careful molecular design of triarylboranes is essential, as strong donor moieties lead to high-lying HOMOs in triarylboranes, creating energetic traps in OPV blends and significantly reducing PCEs. Finally, we demonstrate the application of triarylboranes in semitransparent OPVs, achieving improved PCEs and stability without losing semitransparent performance, and in state-of-the-art PM6/L8-BO-based blends, achieving impressive PCEs of 19.56%. These findings offer valuable guidance for the rational design of triarylboranes for OPVs and related organic electronic applications, reducing reliance on trial-and-error approaches.
作为有机材料中有价值的π电子受体部分，三芳基硼烷家族迅速发展，但三芳基硼烷在有机光伏（OPV）中的性能和应用迄今仍受到限制。在此，我们展示了一个由17种不同三芳基硼烷组成的综合平台，以研究从单晶到异质结共混物再到OPV器件性能的结构-性能关系。我们表明，与先进的OPV材料相比，扭曲的三芳基硼烷在固态中表现出独特的分子堆积行为，其特征是π-π堆积有限，缺乏高效光-电转换所需的面取向。然而，当作为第三组分掺入时，三芳基硼烷会在OPV材料中引起吸收红移和光致发光光谱蓝移，从而降低共混物中的重组能。此外，具有高偶极矩和无陷阱能量学的三芳基硼烷可提高器件的功率转换效率（PCE）。值得注意的是，三芳基硼烷的精心分子设计至关重要，因为强供体部分会导致三芳基硼烷中的最高占据分子轨道（HOMO）较高，在OPV共混物中产生能量陷阱并显著降低PCE。最后，我们展示了三芳基硼烷在半透明OPV中的应用，在不损失半透明性能的情况下实现了更高的PCE和稳定性，在基于最先进的PM6/L8-BO的共混物中，实现了令人印象深刻的19.56%的PCE。这些发现为合理设计用于OPV和相关有机电子应用的三芳基硼烷提供了有价值的指导，减少了对试错方法的依赖。
