Fabrication And Characterizations Of Cu₂O/ZnO P-n Heterojunction And TiO₂-based Dye-sensitized Solar Cells

Solar cells have attracted a lot of interest in recent years with the increasing need for alternative forms of energy.Two types of solar cells are analyzed in this work.First,single-crystal n-type zinc oxide(ZnO)nanorod arrays and p-type cuprous oxide(CuZO)film were used to fabricate Cu2O/ZnO heterostructures through electrochemical deposition.Electrical measurements and external quantum efficiency were used to characterize the properties of the obtained p-n junction.Second,the effects of different electrolytes and counter electrodes on the cell performance were analyzed in order to improve the photoelectric properties of TiO2-based dye-sensitized solar cells(DSSCs),which have seen heavy research since they were invented in 1991.Specifically,for the cell fabrication,iodine-based electrolyte,sulfur-based electrolyte and inorganic solid-state electrolyte CssnI2.95F0.05 were selected to couple with dye-sensitized TiO2 nanorod arrays.The cell composed of CsSnI2.95F0.05 shows the highest conversion efficiency around 8.9%,which is much higher than cells fabricated with the other two electrolytes.To analyze the effects of counter electrodes on the photovoltaic performance of DSSCs,fluorine doped tin oxide transparent conducting glass(FTO),platinum coated FTO(Pt/FTO),graphite coated FTO(Graphite/FTO),and graphite coated common glass(Graphite/glass)were used as the counter electrodes of the TiO2-based DSSCs with CsSnI2.95F0.05.The cells composed of the corresponding electrodes above have power-conversion efficiencies of 2.17%,9.84%,7.62%,and 3.45%,respectively.Our findings indicate that due to its unique catalytic and conducting properties,graphite can replace both Pt and FTO as counter electrode to reduce the fabrication cost of all-solid-state TiO2-based DSSCs.