Novel Sugar Apple-Shaped SnO2 Microspheres with Light Scattering Effect in Dye-Sensitized Solar Cell Application

Novel sugar apple-shaped SnO₂ microspheres with no additives were prepared by facile hydrothermal method and morphological modification was achieved by adding urea as an additive agent at 160 °C. Photoanode materials were characterized using X-ray diffraction, scanning electron microscope, transmission electron microscope, Raman analysis, Fourier transform infrared spectrum, diffuse reflectance spectroscopy, and electrochemical impedance spectroscopy techniques. Sugar apple SnO₂ microspheres and urea-assisted SnO₂ microspheres had rutile crystalline phase with a diameter of 2-3 μm and optical studies showed that the light scattering was observed at a wavelength of 400-800 nm. The novel sugar apple morphology changed into SnO ₂ microspheres composed of nanoparticles with an addition of 0.3 M urea, that is, from pyramidal crystal facets (210 nm) to nanoparticles (22 nm). Dye-sensitized solar cells photoanode film was prepared by doctor blade technique which was dipped in N719 dye. Obtained SnO₂ microspheres were also used as a scattering layer on top of P25 film, and the efficiencies were compared. From I-V curve, the high efficiency of η = 2.76% at a recombination rate of 22.81 ms was obtained for P25/sugar apple SnO₂ microspheres which was because of high light scattering effect of the crystal and the combination of P25.