Bi₂S₃Liquid-Junction Semiconductor-Sensitized SnO₂Solar Cells

Semiconductor-sensitized solar cells (SSCs) are usually fabricated by coating a layer of semiconductor film on a metal oxide TiO 2 photoelectrode. This work demonstrates a new-structure solar cell−Bi 2 S 3 SSCs fabricated on SnO 2 photoelectrodes. Bi 2 S 3 nanoparticles were grown using the successive ionic layer adsorption and reaction process. The Bi 2 S 3 -coated SnO 2 electrodes were fabricated to form liquid-junction solar cells. The best cell yielded a short-circuit current density J sc of 4.20 mA/cm 2 , an open-circuit voltage of 0.16 V, and a power conversion efficiency η of 0.20% under 1 sun. At a reduced light intensity of 10.9% sun, J sc = 0.90 mA/cm 2 (which is equivalent to 8.26 mA/cm 2 under 1 sun) the η increased to 0.27%. The absorbed-photon-to-collected-electron efficiency (APCE) spectrum covered a spectral range of 350−900 nm with a maximal APCE of 64% at λ = 490 nm. These results and the large optical absorption coefficient (α∼10 5 cm −1 ) indicate that Bi 2 S 3 can be used as an absorber for solar cells.