Sb2S3-Sensitized Photoelectrochemical Cells: Open Circuit Voltage Enhancement through the Introduction of Poly-3-hexylthiophene Interlayer

Abstract

The Sb2S3-sensitized photoelectrochemical cells (Sb2S3-SPECs) in cobalt electrolyte were fabricated by depositing Sb2S3 on the macroporous TiO2 nanorods electrodes and consecutively spin-coating P3HT (Poly-3-hexylthiophene) interlayer to relieve the mass transport problem at vicinity of Sb2S3 and cobalt redox couples and reduce the backward recombination. Through the introduction of P3HT interlayer, we could greatly enhance the power conversion efficiency of Sb2S3-SPEC to 4.2% at 1 sun illumination, whereas the Sb2S3-SPEC without P3HT interlayer exhibits 3.2% of device efficiency. The electrochemical impedance analysis let us know that the improved device performance was mainly attributed to the reduced backward recombination building up the higher open circuit voltage.