Improved Quantum Efficiency of Highly Efficient Perovskite BaSnO₃-Based Dye-Sensitized Solar Cells

Abstract

Ternary oxides are potential candidates as an electron-transporting material that can replace TiO₂ in dye-sensitized solar cells (DSSCs), as their electronic/optical properties can be easily controlled by manipulating the composition and/or by doping. Here, we report a new highly efficient DSSC using perovskite BaSnO₃ (BSO) nanoparticles. In addition, the effects of a TiCl₄ treatment on the physical, chemical, and photovoltaic properties of the BSO-based DSSCs are investigated. The TiCl₄ treatment was found to form an ultrathin TiO₂ layer on the BSO surface, the thickness of which increases with the treatment time. The formation of the TiO₂ shell layer improved the charge-collection efficiency by enhancing the charge transport and suppressing the charge recombination. It was also found that the TiCl₄ treatment significantly reduces the amount of surface OH species, resulting in reduced dye adsorption and reduced light-harvesting efficiency. The trade-off effect between the charge-collection and light-harvesting efficiencies resulted in the highest quantum efficiency (i.e., short-circuit photocurrent density), leading to the highest conversion efficiency of 5.5% after a TiCl₄ treatment of 3 min (cf. 4.5% for bare BSO). The conversion efficiency could be increased further to 6.2% by increasing the thickness of the BSO film, which is one of the highest efficiencies from non-TiO₂-based DSSCs.

The Synthesis of Nb-doped TiO2 Nanoparticles for Improved-Performance Dye Sensitized Solar Cells

“…The binding energies of Ti 2p 3/2 (458.6 eV) and Ti 2p 1/2 (464.4 eV) in Fig. 5(a) correspond to Ti 4+ oxidation state, meaning the pure stoichiometric TiO 2 structure [21]. As seen, the Nb-doping causes the peak shift of Ti 2p toward a higher binding energy, which is likely attributed to the larger electronegativity of Nb (1.6) than that of Ti (1.54).…”

Improved charge generation and collection in dye-sensitized solar cells with modified photoanode surface

“…The peak deconvolution process (inset) clearly shows that O 1s spectrum of the reference is composed of two peaks, at 530.1 and 531.4 eV. The peak with lower binding energy is usually associated with the contribution of O 2À ions in ZnO films, whereas the other one with higher binding energy is probably ascribed to the adsorbed hydroxyl groups (-OH) on the surface [26][27][28]. In addition, a peak at 530.9 eV in insets is observed for the surface modified films that are assigned to the lattice oxygen in the TiO 2 .…”

Highly porous Zinc Stannate (Zn2SnO4) nanofibers scaffold photoelectrodes for efficient methyl ammonium halide perovskite solar cells

“…On the other hand, there is no substantial reports are available based on ternary metal oxide (TMO) as electron transporting layer (ETL) for PSC. Shin et al reported nano-particulate BaSnO 3 and Zn 2 SnO 4 ternary metal oxides (TMO) for dye sensitized solar cells, and demonstrated 6.2%, 6%, power conversion efficiency (PCE) respectively1920. Moreover, Zn 2 SnO 4 nanoparticles have been used for PSC and demonstrated ~7% PCE21.…”