Photoelectrochemically deposited Sb2Se3 thin films: deposition mechanism and characterization†
Abstract
Sb2Se3 thin films were photoelectrochemically deposited (PED) and displayed a compelling photoelectrochemical (PEC) performance. The main influence of the illumination mechanism on Sb2Se3 deposition is that the photoconductive effect accelerates the deposition rate and the photogenerated electrons (in the conduction band of the deposited Sb2Se3 thin film) promote the electroreduction of SbO+. Electrochemical impedance spectroscopy (EIS) and potentiostatic polarization show evidence that illumination can promote the rate of cathodic reduction. Linear sweep photovoltammetry (LSPV) and X-ray fluorescence spectrometry (XRF) indicate that illumination facilitates the reduction of SbO+. The PED process can improve the homogeneity and compactness of the films, facilitate the growth of stoichiometric Sb2Se3 and further enhance the photocurrent response of films, compared to the conventional electrochemical deposition (CED) process.