Bi2S3 Liquid-Junction Semiconductor-Sensitized SnO2 Solar Cells

Abstract

Semiconductor-sensitized solar cells (SSCs) are usually fabricated by coating a layer of semiconductor film on a metal oxide TiO2 photoelectrode. This work demonstrates a new-structure solar cell−Bi2S3 SSCs fabricated on SnO2 photoelectrodes. Bi2S3 nanoparticles were grown using the successive ionic layer adsorption and reaction process. The Bi2S3-coated SnO2 electrodes were fabricated to form liquid-junction solar cells. The best cell yielded a short-circuit current density Jsc of 4.20 mA/cm2, 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, Jsc = 0.90 mA/cm2 (which is equivalent to 8.26 mA/cm2 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∼105 cm−1) indicate that Bi2S3 can be used as an absorber for solar cells.