Copper indium sulphide:zinc sulphide (CIS:ZnS)-alloyed quantum dots as an eco-friendly absorber in solar cells

摘要： Synthesis and characterization of less toxic copper indium zinc sulphide (CIS:ZnS)-alloyed quantum dots (QDs) were carried out and the ligand exchange process towards the ef?ciency enhancement in CIS:ZnS QD-sensitized solar cell was demonstrated. The colloidal CIS:ZnS QDs were synthesized by an inexpensive heat up method with oleic acid as the capping ligand. The optical properties were analysed through ultraviolet–visible absorption and photoluminescence emission spectroscopy. The in?uence of the ligand exchange process on the CIS:ZnS QD-based solar cells was analysed with the fabrication of two batches of solar cells. The ligand exchange process was con?rmed from Fourier transform infrared and thermogravimetric analyses. The QD-sensitized solar cells were fabricated using a CIS:ZnS QD-loaded titania photoanode and by employing copper sulphide as the counter electrode. The photovoltaic performance of the fabricated QD solar cells was analysed through photovoltaic characterization methods (current density–voltage characteristics of the devices under the simulated solar light conditions and external quantum ef?ciency measurements). The ligand-exchanged QD-loaded solar cells show enhanced power conversion ef?ciency compared to the long chain ligand-capped CIS:ZnS QD-sensitized solar cells.