Determination of the solubility parameters and agglomeration behaviour of conjugated polymers via a binary solvent gradient method

The efficiency of lab-based, small-area organic photovoltaic (OPV) devices has steadily increased over the last 15 years, increasing from <5% in 2005 to >16% in 2019. The manufacturing of OPV devices relies on the use of solution processing methods such as spin-coating, spray coating and inkjet printing. Therefore, to be processed during device manufacture, conjugated polymers need to have a reasonably high solubility in a given solvent. We have developed a new method to investigate solubility in such materials using a combination of SANS and SESANS which will use in this study. This allows us to investigate the solubility in dark opaque solutions, these are not accessible to traditional UV and visible absorption methods. By studying the solubility we will be able to determine the optimum conjugated polymer types that can be utilised in solar cell fabrication.

近15年来，实验室制备的小面积有机光伏（Organic Photovoltaic, OPV）器件的效率稳步提升，从2005年的不足5%增长至2019年的16%以上。有机光伏器件的制造依赖旋涂、喷涂、喷墨印刷等溶液加工工艺。因此，为满足器件制备过程中的加工要求，共轭聚合物需在特定溶剂中具备较高的溶解度。我们开发了一种结合小角中子散射（Small Angle Neutron Scattering, SANS）与自旋回声小角中子散射（Spin-Echo Small Angle Neutron Scattering, SESANS）的全新方法，本研究将采用该方法来探究此类材料的溶解度。该方法可用于检测深色不透明溶液中的溶解度，而传统紫外-可见吸收光谱法无法对这类溶液开展检测。通过研究此类材料的溶解度，我们能够确定可用于太阳能电池制备的最优共轭聚合物类型。