Department of Physics, Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA.
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Adv Mater. 2018 Feb;30(8). doi: 10.1002/adma.201705485. Epub 2018 Jan 10.
The commercialization of nonfullerene organic solar cells (OSCs) critically relies on the response under typical operating conditions (for instance, temperature and humidity) and the ability of scale-up. Despite the rapid increase in power conversion efficiency (PCE) of spin-coated devices fabricated in a protective atmosphere, the efficiencies of printed nonfullerene OSC devices by blade coating are still lower than 6%. This slow progress significantly limits the practical printing of high-performance nonfullerene OSCs. Here, a new and relatively stable nonfullerene combination is introduced by pairing the nonfluorinated acceptor IT-M with the polymeric donor FTAZ. Over 12% efficiency can be achieved in spin-coated FTAZ:IT-M devices using a single halogen-free solvent. More importantly, chlorine-free, blade coating of FTAZ:IT-M in air is able to yield a PCE of nearly 11% despite a humidity of ≈50%. X-ray scattering results reveal that large π-π coherence length, high degree of face-on orientation with respect to the substrate, and small domain spacing of ≈20 nm are closely correlated with such high device performance. The material system and approach yield the highest reported performance for nonfullerene OSC devices by a coating technique approximating scalable fabrication methods and hold great promise for the development of low-cost, low-toxicity, and high-efficiency OSCs by high-throughput production.
商业化的非富勒烯有机太阳能电池（OSC）严重依赖于典型操作条件下的响应（例如，温度和湿度）和扩展能力。尽管在保护性气氛中制造的旋涂器件的功率转换效率（PCE）迅速提高，但刮刀涂布的印刷非富勒烯 OSC 器件的效率仍低于 6%。这种缓慢的进展极大地限制了高性能非富勒烯 OSC 的实际印刷。在这里，通过将非氟化受体 IT-M 与聚合物给体 FTAZ 配对，引入了一种新的、相对稳定的非富勒烯组合。在使用单一无卤溶剂的旋涂 FTAZ：IT-M 器件中，可实现超过 12%的效率。更重要的是，尽管湿度约为 50%，但在空气中使用无氯、刮刀涂布的 FTAZ：IT-M 仍能获得近 11%的 PCE。X 射线散射结果表明，大的 π-π 相干长度、相对于基底的高面外取向度和≈20nm 的小畴间距与如此高的器件性能密切相关。该材料系统和方法通过近似可扩展制造方法的涂层技术实现了非富勒烯 OSC 器件的最高报道性能，为通过高通量生产开发低成本、低毒性和高效率的 OSC 提供了巨大的前景。
