Although research in the field of organic photovoltaics (OPV) still merely focuses on efficiency, efforts to increase the sustainability of the production process and the materials encompassing the device stack are of equally crucial importance to fulfil the promises of a truly renewable source of energy. In this study, a number of steps in this direction are taken. The photoactive polymers all contain an electron-deficient building block inspired on the natural indigo dye, bay-annulated indigo, combined with electron-rich thiophene and 4H-dithieno[3,2-b:2′,3′-d]pyrrole units. The synthetic protocol (starting from indigo) is optimized and the final materials are thoroughly analyzed. MALDI-TOF mass spectrometry provides detailed information on the structural composition of the polymers. Best solar cell efficiencies are obtained for polymer:fullerene blends spin-coated from a pristine non-halogenated solvent (o-xylene), which is highly recommended to reduce the ecological footprint of OPV and is imperative for large scale production and commercialization.

尽管有机光伏（OPV）领域的研究仍仅着眼于效率，但为提高生产过程的可持续性而做出的努力以及包含器件堆栈的材料对于实现真正可再生能源的承诺也同样至关重要。在这项研究中，朝这个方向采取了许多步骤。所有的光敏聚合物都包含一个受自然靛蓝染料启发的缺电子结构单元，月桂色靛蓝，富电子噻吩和4 H-二硫代[3,2- b：2'，3'- d]吡咯单元。优化了合成方案（从靛蓝开始），并对最终材料进行了全面分析。MALDI-TOF质谱提供了有关聚合物结构组成的详细信息。对于从原始非卤代溶剂（邻二甲苯）旋涂的聚合物：富勒烯共混物，可获得最佳太阳能电池效率，强烈建议降低其对OPV的生态足迹，这对于大规模生产和商业化是必不可少的。