Fabrication of Barium Titanate Nanowires-GNP Composite Bilayer Photoanodes for the High-Performance Dye-Sensitized Solar Cells

Inorganic perovskite barium titanate nanowires (BTNWs) and their nanocomposites comprised of different weight percentages (1, 2, and 3 wt%) of graphene nanoplatelets (GNP) are synthesized via a hydrothermal method and used as photoanode materials of dye-sensitized solar cells (DSSCs). Morphological analysis of the BTNWs and BTNWs + GNP composites has indicated that the one-dimensional BTNWs and two-dimensional GNP are formed as uniformly distributed, well-connected mesoporous microstructures. UV-visible absorption and Raman studies of the BTNWs + GNP composites have revealed a narrowing bandgap, improved visible light absorption with increasing GNP content, and a superior light-scattering effect of BTNWs. Besides, four different DSSC bilayer photoanodes comprising titanium dioxide nanoparticles (TNP) underlayer and an upper layer with BTNWs + (0, 1, 2, and 3 wt%) GNP composites are fabricated to elucidate the TNP + BTNWs and BTNWs + GNP composite sublayer(s) influences on the photovoltaic performance. The TNP + BTNWs + 2 wt% GNP composite bilayer photoanode has demonstrated a higher power conversion efficiency of 9.92 % as compared to that of the other TNP + BTNWs + GNP composite bilayer photoanodes in DSSCs, due to the higher charge recombination resistance, faster charge transport, superior charge collection ability and carrier lifetime of its sublayers.

Automated summary

Inorganic perovskite barium titanate nanowires (BTNWs) and their nanocomposites with graphene nanoplatelets (GNP) were synthesized and used as photoanode materials in dye-sensitized solar cells (DSSCs). The BTNWs and BTNWs + GNP composites showed well-connected mesoporous microstructures and improved light-scattering effects. The TNP + BTNWs + 2 wt% GNP composite bilayer photoanode achieved the highest power conversion efficiency in DSSCs due to its superior sublayer properties.