Upconversion 32Nb_(2)O_(5)-10La_(2)O_(3)-16ZrO_(2) glass activated with Er^(3+)/Yb^(3+) and dye sensitized solar cell application

Er^(3+)/Yb^(3+)codoped niobium pentoxide glasses were fabricated by the aerodynamic levitation(ADL)method with rapid cooling rate.All samples with various doping concentrations showed good upconversion luminescence properties under 980 nm laser excitation.The structure,transmittance spectrum,and luminescence properties of the samples were systemically investigated by XRD,UV-Vis-NIR spectrophotometer,and upconversion spectra.All transparent samples exhibited green and red upconversion emissions centered at 532,547,and 670 nm.Experimental results showed that the sample codoped with 1 mol%Er^(3+)/Yb^(3+)has the strongest upconversion emissions,and the increase of the doped Yb^(3+)concentration results in the increased red emission and reduced green emission.The logI-logP plot of green emission indicated that the green emissions reach the saturation at high pump power excitation,deviating from the low-power regime.After one-photon energy transfer(ET)process,^(4)I_(11/2)+^(4)I_(11/2)→^(4)F_(7/2)+^(4)I_(15/2) process between the two neighboring Er^(3+)ions was responsible for the population of the 4S3/2/4H11/2 states.The niobium pentoxide codoped with Er^(3+)/Yb^(3+)bulk glasses could be used in the dye sensitized solar cell(DSSC)to improve the efficiency.