A computational approach on engineering short spacer for carbazole-based dyes for dye-sensitized solar cells

•Short spacers were designed for carbazole-based dyes using computational approach.•Effect of electron donating and withdrawing groups was examined using DFT/TD-DFT.•Introduction of CN group at the linker enhances the intramolecular charge transfer.•Tolyl substituent at carbazole unit stabilizes the oxidized dye through resonance.•Introduction of CN at linker reduces the EH-L, while OMe increases the EH-L.