A comparative study of low-cost coating processes for green & sustainable organic solar cell active layer manufacturing

Owing to their facile integration into existing commercial products, high volume manufacturing of organic solar cells (OSCs) can be expected in the upcoming years. Therefore, it is important evaluate performance and sustainability various active layer coating methods for OSCs. Herein, we compare four processes: spin-coating, blade-coating, spray-coating push-coating poly(2,7-carbazole-alt-dithienylbenzothiadiazole):[6,6]-Phenyl-C71-butyric acid methyl ester (PCDTBT:PC71BM) layers deposition. The optical, morphological photovoltaic parameters are studied. suitability each method industrial PCDTBT:PC71BM OSCs discussed terms environmental impact, necessary investments running costs. Our results confirm that, despite producing quality OSCs, spin-coating unsuitable due large amounts materials hazardous solvents wasted process. Blade-coating provides a good balance between low costs, impact decent performances but process introduces lateral compositional gradients which could detrimental area OSC processing. Spray-coating requires minimal initial has relatively sustainability. Push-coating yields perform as well spin-coated ones, with much lower cost. We should thus look forward seeing whether this green sustainable technology develop future.