Incorporation of Al-(hydr)oxide species onto the surface of TiO2 nanoparticles: Improving the open-circuit voltage in dye-sensitized solar cells

Abstract

This study presents the incorporation of Al-(hydr)oxide species onto the surface of TiO2 nanoparticles used as photoelectrodes in dye-sensitized solar cells. The semiconductors prepared were comprehensively characterized by means of atomic absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and UV–vis spectroscopy. The percentages of Al incorporated onto the TiO2 surface were obtained, the maximum being 6.45wt.% (Al/TiO2). The presence of Al-(hydr)oxides in the samples was also determined, and was shown not to affect the crystalline phases present, as well as affecting the amount of dye that the semiconductors were able to absorb. These results are evidence of the presence of Al-(hydr)oxide species on the surface. Furthermore, the use of the semiconductors prepared as photoelectrodes in DSSCs led to an increase in open-circuit voltage of up to 16%.