Effect of deposition time on photoelectrochemical performance of chemically grown Bi_2Se_3-sensitized TiO_2 nanostructure solar cells

摘要

This paper explore the ability of bismuth selenide (Bi_2Se_3) as an alternative light sensitizer for photoelectrochemical (PEC) solar cell. Herein, we applied novel chemical route, namely, chemical bath deposition (CBD) for growth of Bi_2Se_3 nanoparticles over spin-coated TiO_2 at room temperature. The structural, surface morphological, and optical properties of TiO_2/Bi_2Se_3 films are systematically studied. The deposition time for the growth of Bi_2Se_3 using CBD can enable to tune the size of Bi_2Se_3 nanoparticles over porous TiO_2 which significantly influences the physical properties of resultant heterostruciure. The potential of Bi_2Se_3 nanoparticles in PEC solar cell is demonstrated by preparing FTO|TiO_2 | Bi_2Se_3 | polysulphide electrolyte | carbon-coated FTO device structure and tested with current density-voltage (J-V) and electrochemical impedance spectroscopy (EIS) measurements. The result presented in this study established that the photoconversion efficiency and electron life time of device are affected by deposition time for Bi_2Se_3 using CBD. The J-V measurement done with above-proposed devices shows maximum photoconversion efficiency around 0.152% for 20 min deposited Bi_2Se_3.