Photogenerated-carrier separation along edge dislocation of WO3 single-crystal nanoflower photoanode

Abstract

Point defects, such as oxygen vacancies in semiconductors, have been widely proven to influence the separation and transfer processes of the photogenerated hot charges. Besides point defects, to date, scarcely any study has focused on expounding the functions of line defects (such as dislocations) in the crystal of semiconductor photoanodes and influencing the photogenerated hot charge separation process. Herein, a nanoflower (NF)-like WO₃ single-crystal thin film photoanode with edge dislocations is reported. The dislocation induces mismatch of the (002) and (020) facets. Further photoelectrochemical (PEC) performance and DOS calculation results indicate that a heterojunction system could be formed along the edge dislocations due to the energy difference between the mismatched (002) and (020) facets. Therefore, this present study provides an understanding of the line defect in the photogenerated hot carrier separation process and a novel method to improve the properties of photoelectrodes and photocatalytic materials in the near future.