NAYF₄:Yb³⁺,Tm³⁺ Microrods Doping In TiO₂ Photoanode To Enhance Photon Harvesting In Dye-sensitized Solar Sells

Photoanode is the core component of dye-sensitized solar cells?DSSC?.Its performance directly affects the device performance.The sensitized dye N719 widely used in the study has good absorption in the visible region,but it has poor absorption in the infrared and near infrared regions.The photoanode of the doped upconversion material is an effective way to broaden the absorption spectrum of the dye.This paper introduces an effective method to improve the efficiency of DSSC by using upconversion microrods NaYF₄:Yb³⁺,Tm³⁺doped in TiO₂ photoanode to improve the infrared radiation capture of the sun light.Photoluminescence upconversion NaYF₄:Yb³⁺,Tm³⁺particles under different conditions were prepared by hydrothermal method.Their physical and optical properties were studied by scanning electron microscopy?SEM?X ray diffraction?XRD?and photoluminescence upconversion and downconversion spectra.The energy transfer mechanism of upconversion and downconversion of NaYF₄:Yb³⁺,Tm³⁺particles is discussed.The effects of different composition,size and morphology of NaYF₄:Yb³⁺,Tm³⁺particles on their upconversion efficiency have been studied.The results show that the hexagonal microrods of composition NaYF₄:Yb³⁺?10%?and Tm³⁺?1%?are the best.The UC NaYF₄:Yb³⁺,Tm³⁺particles were doped in the TiO₂ photoanode for DSSC.The results show that the addition of a small amount of these micron rods enhances the optical capture ability of the photoanode,thus enhancing the photocurrent conversion.These rare earth ions are p type dopants,which increase the energy levels of TiO₂ thin films and thus enhance the photovoltage.The optimum ratio of NaYF₄:Yb³⁺,Tm³⁺to TiO₂?by weight?is 5:100.For 5%NaYF₄:Yb³⁺,Tm³⁺@TiO₂ as the photoanode,the maximum photoelectric conversion of the battery is 7.03%.The efficiency?7.03%?is 17%higher than that of the pure TiO₂ photoanode?6.13%?.This improvement can be attributed to the upconversion properties of doped materials.