Journal of Power Sources, Vol.243, 436-443, 2013
Er3+ and Yb3+ co-doped TiO2-xFx up-conversion luminescence powder as a light scattering layer with enhanced performance in dye sensitized solar cells
Er3+ and Yb3+ co-doped TiO(s)2_5F5 up-conversion luminescence powder (UC-TiO2_5F5) was fabricated via hydrothermal method and calcined at 500 C for 2 h. The prepared powders were characterized by SEM, XRD, PL, UC-PL, UV-Vis, SPS and IPCE spectra. The results showed that UC-Ti:(2)_5F5 possessed the property of up-conversion, increasing the percentage of visible light that can be absorbed by N719 dyes; it got a lower band gap energy which contributed to a faster electrons injection and decreased the radiative recombination process of photo-generated electrons and holes in TiO2; and adequate F-doping could enhance the performance of luminescence and widened the light absorption in visible light range, but excessive Fdoping could cause blue-shift. We applied the UC-TiO2-5F5 into dye sensitized solar cell (DSSC), as a light scattering layer for its special morphology, to gain a higher light harvesting and a lower light loss so as to achieve a satisfied DSSC efficiency. Under the simulated solar irradiation of 100 mW cm(-2) (AM1.5G), a short-circuit current density of 16.3 mA cm(-2), an open-circuit voltage of 0.725 V and an overall energy conversion efficiency of 7.08% were obtained by introducing this light scattering layer. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Er3+-Yb3+ co-doped TiO2-F-x(x) (UC-TiO(2-xF)x);Up-conversion;Light scattering layer;Dye sensitized solar cell