30 PbS(2)CdS(10) 0.39 9.09 0.30 1.05 PbS(1)CdS(10) 0.36 5.24 0.24 0.46 V oc, open-circuit voltage; J sc, short-circuit photocurrent density; FF, fill factor; η, energy conversion efficiency. With further improvement of their performance, this kind of PbS/CdS co-sensitized TiO2 nanorod solar cells may play a promising role in the future due to the following

reasons: (1) The bandgap of PbS nanoparticles is quite small and extends the absorption band towards the NIR part of the solar spectrum, which will result in a high current density. (2) TiO2 nanorod arrays grown directly selleck chemical on FTO conductive glass avoid the particle-to-particle hopping that occurs in polycrystalline mesoscopic TiO2 films, which can also contribute to a higher efficiency. (3) TiO2 nanorods form a relatively open structure, which is advantageous over the diffusion problems associated with the redox couples in porous TiO2 network. In our present work, the cell efficiency was still not high enough for practical application. The drawback limiting

the energy conversion efficiency of this type of solar cells was the rather poor fill factor. This low fill factor may be ascribed to the lower hole-recovery rate of the polysulfide electrolyte, leading to a higher probability 4SC-202 research buy for charge recombination [26]. To further improve the efficiencies of these PbS/CdS-TiO2 nanostructured solar cells, a new hole transport medium with suitable redox potential and low electron recombination at the semiconductor-electrolyte interface should be developed. Counter electrode was another this website important

factor influencing the energy conversion efficiency. Recently, Sixto 4-Aminobutyrate aminotransferase et al. [27] and Seol et al. [28] reported that the fill factor was clearly influenced by counter electrode materials where Au, CuS2, and carbon counter electrode show better performance than Pt ones. Moreover, deposition of a ZnS passivation layer on the photoanode after the PbS/CdS sensitization would greatly eliminate interfacial charge recombination and improve the photovoltaic performance of PbS/CdS-TiO2 nanostructured solar cells [29]. Further work to improve the photovoltaic performance of these solar cells is currently under investigation. Conclusion In this study, large-area ordered rutile TiO2 nanorod arrays were utilized as photoanodes for PbS/CdS co-sensitized solar cells. Narrow bandgap PbS nanoparticles dramatically increase the obtained photocurrents, and the CdS capping layer stabilizes the solar cell behavior. The synergistic combination of PbS with CdS provides a stable and effective sensitizer compatible with polysulfide. Compared to only PbS-sensitized solar cells, the cell power conversion efficiency was improved from 0.2% to 1.3% with the presentation of a CdS protection layer. The PbS/CdS co-sensitized configuration has been revealed to enhance the solar cell performance beyond the arithmetic addition of the efficiencies of the single constituents.