FABRICACIÓN Y CARACTERIZACIÓN DE FOTOELECTRODOS TRANSPARENTES ALTAMENTE CONDUCTORES Y DE GRAN TAMAÑO PARA PRODUCCIÓN DE ENERGÍA FOTOVOLTAICA Y ALMACENAMIENTO.

Abstract

In this work relatively large size photoelectrodes (18.75cm^2 of surface) and very low sheet resistance has been manufactured. The manufacturing method was the spray pyrolysis of a solution containing Sn2+ and F- ions. It was grown a thin film of tin dioxide doped with fluorine (SnO2:F) on thin glass substrates (1.2 mm thick). Different photoelectrodes using various mass doping element percentages (0%, 10%, 15%, 16%, 19% and 20% [F]/[Sn]). The samples were characterized morphologically and studied their chemical composition and optical and electrical properties. The results show that the film grown on glass substrate is high purity tin dioxide with crystallization in the tetragonal rutile system and spatial group D144h(P42/mnm). SEM pictures show a relatively smooth surface, little roughness and thickness about 500 nm. Moreover, the roughness decreases as the doping level. The photowindows are very transparent to visible light (400-800 nm), with optical transmittance about 85 % and absorbance about 0.25au. The best value of sheet resistance of the conductive layer, for a doping of 16%, is around 3 Ω cm^-2, improving results reported by other authors, the resistivity (12+-6)x10^-5Ωm and the density 2.45x10^4 kgm^3.