Organic solar cells are considered to be new energy technologies with significant application prospects due to their outstanding advantages such as light weight, flexibility, and the ability to prepare large-area devices. Since the photovoltaic performance of bulk heterojunction solar cells depends largely on the morphology of the active layer, Hou Jianhui, a researcher of the Polymer Physics and Chemistry Laboratory, Institute of Chemistry, Chinese Academy of Sciences, has carried out a series of work on optimizing the morphology of the active layer ( Adv. Mater. 2012, 24, 6335-6341; J. Phys. Chem. C 2013, 117, 14920-14928; Adv. Mater. 2017, 29, 1703777). As the main method to optimize the morphology of the active layer of organic solar cells, the use of high-boiling solvent additives, such as 1,8-diiodooctane, can effectively improve the photovoltaic performance of the device. However, this method has serious problems in the mass production of organic solar cells, especially residual high-boiling solvent additives will affect the stability and reproducibility of the device. In recent years, due to its strong absorption, high tunability and good stability, non-fullerene receptors have attracted extensive attention in the field and achieved very outstanding results. With the in-depth study of such non-fullerene solar cells, the researchers found that the accumulation structure of the end groups of such receptor molecules has an important impact on their charge transport performance. Recently, with the support of the National Natural Science Foundation of China, the Ministry of Science and Technology and the Chinese Academy of Sciences, researchers have designed and synthesized a class of volatile solid additives based on the molecular structure characteristics of non-fullerene receptors. Such volatile solid additives have a chemical structure similar to the end groups of non-fullerene receptors, which can effectively promote the orderly arrangement of non-fullerene receptors and improve the charge transport performance of the active layer, thereby effectively improving the photoelectric conversion of the device effectiveness. The researchers have studied in detail the influence of additives on the morphology of the active layer and proposed the working mechanism of such additives, and have also proved through experiments that devices made with volatile solid additives have better performance than battery devices treated with solvent additives. Stability and reproducibility. The research results were published in the recent Nature-Communications (Nat. Commun. 2018, 9, 4645). 8pcs folding torx key set, torx key set,key set tool, torx key set tool,folding torx key henan horn tools co.,ltd. , https://www.hornhandtools.com
Figure: Schematic diagram of the working mechanism of volatile solid additives and optimized device performance