All-polymer solar cells (APSCs) are highly regarded for their exceptional light and thermal stability as well as their flexibility, making them a prime candidate for use in flexible power systems. Recent advancements in non-fullerene acceptor materials have spurred the creation of high-performing small molecule receptors. However, the development of high-efficiency polymer donors has lagged behind. Designing and synthesizing new polymer donor materials, understanding how to regulate the stacking and orientation of donor/acceptor molecules, and clarifying their relationship with photovoltaic performance could significantly enhance the efficiency of APSCs.
Recently, the research team led by Dr. Bao Xichang from the Qingdao Institute of Bioenergy and Process, part of the Chinese Academy of Sciences, has made significant strides in this area. They successfully designed and synthesized a new ultra-wide bandgap polymer donor material (Eopt = 2.24 eV), minimizing charge transfer states and quinone resonance effects within the donor's main framework. This material boasts a high extinction coefficient and an absorption spectrum that perfectly matches the strongest solar radiation wavelengths. It also demonstrates excellent compatibility with acceptor materials and strong intermolecular interactions. The resulting binary and ternary APSCs achieved efficiencies of 15.3% and 17.1%, respectively, outperforming current classic donor materials. This study offers innovative design principles and material structures for future donor materials in all-polymer solar cells. The findings have been published in *Advanced Functional Materials*.
Another challenge lies in the strong inter-chain entanglement of conjugated polymers, which often leads to poor phase separation and low mixing entropy, complicating the regulation of active layer crystallization and morphology. To address this, the researchers developed a well-miscible polymer donor that effectively infiltrates donor/acceptor (D/A) aggregation domains, optimizing molecular accumulation and phase separation in all-polymer active layers. This approach maximizes exciton and carrier utilization. A ternary APSC with a bulk heterojunction (BHJ) structure achieved an impressive efficiency of 17.64% and exhibited excellent thick film tolerance. The ability of the third component to promote mixed-phase formation and independently optimize D/A accumulation showcases its unique advantages in constructing ideal pseudo-plane heterojunction (PPHJ) active layers. Ternary APSCs with PPHJ structures achieved an efficiency of 17.94% and demonstrated remarkable device stability. Utilizing the third component’s miscibility to induce ordered D/A accumulation holds immense potential for creating high-performance APSCs. These results have been published in *Energy & Environmental Science*.
This research was supported by grants from the National Natural Science Foundation of China, the Ministry of Science and Technology’s international cooperation projects, and the special funds of the Shandong Energy Research Institute.
**Figure 1.** A novel molecular strategy to construct efficient polymer donor materials.
**Figure 2.** A ternary strategy to optimize molecular aggregation in the absorbing layer.
Cpu Cooler,Crown Amd Cpu Cooler,Crown Cpu Cooler Fan,Intel Cpu Cooler Fan
Crown Electronics CO., LTD , https://www.crownhaero.com