tailieunhanh - Solar Cells Dye Sensitized Devices Part 12

Tham khảo tài liệu 'solar cells dye sensitized devices part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 322 Solar Cells - Dye-Sensitized Devices nanoparticle aggregates and the rapid electron transport rate and the light scattering effect of single-crystalline nanowires Tan et al. 2006 . An enhancement of power efficiency from for pure nanoparticle cells to for the composite cell with 20 wt nanowires was achieved showing that employing nanoparticle nanowire composites represented a promising approach for further improving the efficiencies of DSCs. c. H. Ku et al. reported ZnO nanowire nanoparticle composite photoanodes with different nanoparticle-occupying extents Ku et al. 2008 . Aligned ZnO nanowires were grown on the seeded FTO substrate using an aqueous chemical bath deposition CBD first and then growth of nanoparticles among ZnO NWs by another base-free CBD was preceded further for different periods. The corresponding DSCs showed an efficiency of indicating the good potential of the hybrid nanostructures in ordered photoanodes. Apart from the direct blending of two different semiconductor components as mentioned above the coating technique has also been applied widely to create the hybrid photoanodes. M. Law et al. developed photoanodes constructed by ZnO nanowires arrays coated with thin shells of amorphous AI2O3 or anatase T1O2 by atomic layer deposition Law et al. 2006 . They found that while alumina shells of all thicknesses acted as insulating barriers that improve cell open-circuit voltage only at the expense of a larger decrease in short-circuit current density titania shells in thickness of 10-25 nm can cause a dramatic increase in Voc and fill factor with little current falloff resulting in a substantial improvement in overall conversion efficiency . They attributed the improved performance to the radial surface field within each nanowire that decreases the rate of recombination. K. Park et al. described a ZnO-TiC 2 hybrid photoanode by coating ultrathin T1O2 layer by atomic layer deposition on submicrometer-sized aggregates of ZnO .