Preparation of Gd2O3:Eu3+ downconversion luminescent material and its application in dye-sensitized solar cells

Abstract

Gd 2 O 3 :Eu 3+ downconversion luminescent powder was prepared using the homogeneous precipitation method. Its optical properties were analyzed and it was introduced into a dye-sensitized solar cell (DSSC). As a luminescence medium, Gd 2 O 3 :Eu 3+ improved light harvesting via conversion luminescence and increased the photocurrent of the DSSC. As a p-type dopant insulating rare earth oxides form an energy barrier, and the Gd 2 O 3 :Eu 3+ elevated the energy level of the oxide film and increased the photovoltage. The photoelectric conversion efficiency for a DSSC with Gd 2 O 3 :Eu 3+ doping (6 : 100) reached 7.01%, which was 17.4% higher than the photoelectrical conversion efficiency of a DSSC without Gd 2 O 3 :Eu 3+ doping. dye-sensitized solar cell, downconversion, rare-earth oxide, luminescent material, p-type doping Citation: Li Q B, Lin J M, Wu J H, et al. Preparation of Gd 2 O 3 :Eu 3+ downconversion luminescent material and its application in dye-sensitized solar cells. Considerable effort has been devoted to the dye-sensitized solar cell (DSSC) since the first prototype was reported by O'Regan et al. [1] and Gratzel [2]. There has been great progress in development of the DSSC over the past decade, because of its low cost, simple preparation, and conversion efficiency which has reached 11% [3]. In general, the sensitizer of the DSSC contains mainly N3 and N719 dyes [1-6], and the DSSC consists of a porous nanocrystalline TiO 2 film sensitized by a dye for absorbing incident light. However, even the best of these dyes (N719) absorbs only visible light in the wavelength range 300-800 nm, while the standard air-mass (AM1.5) terrestrial spectrum covers the wavelength region from UV to IR (200-2500 nm). Downconversion materials are a viable option for reducing the spectral mismatch losses. Trupke et al. [7] have suggested that the dye molecules in a DSSC could avoid the absorption of high-energy photons in a conventional semiconductor solar cell with infinite bands, by directing the high-energy part of the solar spectrum toward a downconverter with suitable low-pass mirrors. However, few studies have been carried out on the use of conversion luminescence in the DSSC. Our group [8] has reported work in which Y 2 O 3 :Eu 3+ nanophosphor was prepared by the co-precipitation method. As a luminescence medium Y 2 O 3 :Eu 3+ improved light harvesting via a conversion luminescence process and increased the photocurrent. As a p-type dopant, Y 2 O 3 :Eu 3+ elevated the energy level of the oxide film and increased the photovoltage. In the present study, Gd 2 O 3 :Eu 3+ nanophosphor was prepared by the homogeneous precipitation method [9,10]. Since Gd 2 O 3 is isostructural with Y 2 O 3 , Gd 2 O 3 :Eu 3+ can be used as a phosphor and is comparable to Y 2 O 3 :Eu 3+ . Gd 2 O 3 :Eu 3+ has been reported to be a more effective phosphor than Y 2 O 3 :Eu 3+ for particular applications such as an X-ray scintillator, because Gd 2 O 3 has higher density and light efficiency [11]. In addition, the synthesis of Gd 2 O 3 :Eu 3+ phosp...

Thermal degradation of BaAl2Si2O8:Eu2+ phosphor excited by near ultraviolet light

“…The phosphor Ba 1-x 3 . The mixture was stirred and heated at 353 K for 1 h, and then an appropriate amount of precipitator (NH 4 HCO 3 (A.R., Kelong)) was added.…”

“…white light emitting diodes (LEDs) fabricated with near ultraviolet (UV) chips [1][2][3][4]. The emission spectrum of Eu 2+ ions is usually comprised of broad bands that range from UV to red regions caused by transitions between the 4f 7 ground state and the crystal field components of the 4f 6 5d…”

Lanthanides in Solar Energy Conversion

“…Another host material, Gd 2 O 3 , gives slightly better results when it contains 6 mol% of Eu III and when the mole ratio Gd:Ti is 6% (see Table 7, entry 7; Li et al, 2011a). Under UV-irradiation (l < 420 m), the cell yield increases from 1.5% to 1.9% upon doping Gd 2 O 3 :Eu into the TiO 2 electrode, the difference (0.4%) being consistent with the yield of a cell containing only the Eu phosphor.…”

Applications of Oxide Coatings in Photovoltaic Devices

“…The down-converter should ideally have an energy band gap double as wide as that of the PV absorber and should possess impurity levels at the centre. Gd 2 O 3 :Eu nanocrystals dispersed in mesoporous TiO 2 enhance the DSSC efficiency by excitation of Gd 2 O 3 by UV light which transfers charge to Eu then onto the TiO 2 [170]. In another configuration, through Eu 3+ and Sm 3+ doping, UV light absorbed by mesoporous TiO 2 can be re-emitted over a relatively broad band from 550 to 750 nm [171].…”