Impact of Ferroelectric Polarization on Different Semiconductors for Photoelectrochemical Application

Abstract

Introducing a built-in electric field into photoelectrochemical (PEC) system is considered as an effective strategy to tune interfacial energy band bending and manipulate charge transport direction. Here, we design the hybrid ferroelectric-semiconductor structure photoanodes for water oxidation, and the BaTiO3 is used for ferroelectric while monoclinic WO3, tetragonal TiO2, and triclinic CuWO4 for the semiconductors respectively. After the positive poling, 3 wt% BTO-WO3 and 3 wt% BTO-CuWO4 hybrid photoanodes perform significantly enhanced photocurrent of 68.5% and 62.9% compare with the pristine semiconductors. The efficiencies of charge separation and oxidation kinetics of these hybrid photoanodes increase by 14-19% and 1.38-1.42 fold, and the electron transport time decreases by 16%. Further, Kelvin probe force microscopy measurements indicate that the surface potential of hybrid structure is lower than unmodified samples, suggesting the space charge region near the semiconductor surface has been change...