Electrodeposited Aluminum-Doped alpha-Fe2O3 Photoelectrodes: Experiment and Theory

Abstract

Substitutional doping call improve the electronic Properties of alpha-Fe2O3 for the solar photoelectrochemical (PEC) applications. Generally speaking, nonsovalent substitutional doping helps to enhance the electronic conductivity of alpha-Fe2O3. However, We found that file introduction of strain ill the lattice, which is achieved by isovalent substitutional doping of an Al, call also improve the electronic properties. alpha-Fe2O3 films with the Al dopant atomic concentration varying from 0 to 10%, were prepared by electrodeposition, and their performance for photoelectrochemical hydrogen production was characterized. Results indicate that the incident photon conversion efficiency (IPCE) for similar to 0.45 at-% Al substitution increases by 2- to 3-fold over undoped samples. Density-functional theory (DFT) was Utilized to interpret the experimental findings. It wits shown that although no substantial change to the electronic structure, it contraction of the crystal lattice due to the isovalent replacement of Fe3+ by an Al3+ benefits the small polaron migration, resulting ill an improvement in conductivity compared to the undoped samples.