Fabrication, device performance, and MPPT for flexible dye-sensitized solar panel based on gel-polymer phthaloylchitosan based electrolyte and nanocluster CoS2 counter electrode

Abstract

In this work, we fabricated solar cells and panel using net-like CoS2 nanostructure as Counter Electrode (CE) spray coated on Ag grid embedded on flexible plastic Poly-Ethylene Terephthalate (PET) substrate. The spray coated CoS2 thin film revealed its form to be a hierarchical net-like nano-structure. The TiO2:N3 dye and phthaloylchitosan-based gel-polymer electrolyte as the redox electrolyte layers of Flexible Organic Solar Panel (FOSP) was fabricated using screen printing technique. Then both segments were sandwiched to form flexible solar panel. The fabricated solar cell showed a Power Conversion Efficiency (PCE or η) of 7.09% with a fill factor (FF) of 0.64, Jsc of 17.51 mA/cm2, and an open circuit voltage (Voc) of 0.65 V, which was comparable to that of Platinum (Pt) CE (η = 7.82%). Similarly, for FOSP showed PCE of 7.04%, FF of 0.62, Isc of 67 mA and Voc of 60 V. The FOSP was connected to buck converter with Maximum Power Point Tracking (MPPT) using a modified Fractional Open Circuit Voltage (FOCV) combined with Duty-cycle Derivative of Output Voltage (DDOV) algorithms, Buck Boost converter (BBC) works from 60 to 5.8 V in buck mode, the output is connected to a battery. For voltages less than 8 V the power converter works in boost mode (up to 3.8 V), a micropower harvester would be very useful many handheld gadgets.