Aza-dipyrrinato ruthenium sensitizers for enhancement of Light-Harvesting ability of Dye-Sensitized solar cells

•Three new aza-dipyrrinato ruthenium sensitizers AZA-BPY, AZA-BPY-NCS, and AZA-TER have been designed and synthesized.•Aza-dipyrrinato ancillary ligand showed better light-harvesting capability compared to the traditional dipyrrinato ligand.•We have observed the panchromatic absorption (250 nm to 1000 nm) in aza-dipyrrinato ruthenium sensitizers.•We successfully demonstrated the tuning of optical properties of sensitizer by tailoring of dipyrrinato ancillary ligands.