The application of a novel D−A− π − A phenothiazine-based organic dye with N719 in efficient parallel tandem dye-sensitized solar cells

In this study, an innovative D−A− π − A 2-phenothiazine-phenylamine-based organic dye PTZ-15 was synthesized and confirmed to own compatibility and helpfulness with the classical ruthenium dye N719 in the aspect of light-harvesting. Hence, the T-DSSCs with a doubled-sided Pt electrode which were composed of a N719-based top cell and a PTZ-15-based bottom cell in the parallel connection were manufactured and the corresponding performance was tested. The parallel tandem DSSCs (PT-DSSCs) exhibited a substantially increased short-circuit photocurrent density (Jsc) of 20.62 mA·cm−2 and photoelectric conversion efficiency (PCE) of 10.85 % relative to the conventional DSSCs based on single N719 or PTZ-15. In terms of such findings, we afford a strategy for driving the further development of the high-efficient T-DSSCs.