Panchromatic absorption of dye sensitized solar cells by co-Sensitization of triple organic dyes

Abstract

Dye sensitized solar cells (DSSCs) were co-sensitized with three custom molecularly engineered organic dyes containing butyloxyl chain induced dye (Y1), boron dipyrromethene (bodipy) dye (TP₂A), and squaraine (SQ) ring configured dye (HSQ4). The individual power conversion efficiencies of the DSSCs sensitized with Y1, TP₂A and HSQ4 sensitizers were 3.44%, 4.26% and 5.78%, respectively. Co-sensitized TP₂A + HSQ4 dyes at a 2 : 1 molar ratio showed an efficiency of 7.02%. Further addition of Y1 dye with optimal TP₂A + HSQ4 increased the V_OC from 0.580 V to 0.605 V. The co-sensitized Y1 + TP₂A + HSQ4 based DSSCs showed a new optimal efficiency (η) of 7.48%. This is the highest efficiency recorded for DSSCs based on co-sensitization of triple organic dyes. Intensity modulated photovoltage spectroscopy further confirms the longer lifetime of co-sensitized Y1 + TP₂A + HSQ4 compared to that of each individual TP₂A and HSQ4 and co-sensitized TP₂A + HSQ4 dye.