Substantial Lifetime Enhancement of Si-Based Photoanodes Enabled by Amorphous TiO2 Coating with Improved Stoichiometry

A method of removing precursor ligands and byproducts in a photoelectrode, the method comprising:

• (a) performing an atomic layer deposition of an oxide onto a photoanode material including the steps of:
• pulsing oxygen precursors onto a photoanode material surface;
• purging the photoanode material surface with an inert gas;
• pulsing metal precursors onto the photoanode material surface;
• and
• purging the photoanode material surface with the inert gas
• to deposit a thin film of oxide onto the photoanode material surface to produce a thin film matrix;
• (b) performing a water treatment of the thin film matrix including the steps of:
• pulsing the oxygen precursors onto the thin film matrix;
• and
• purging the thin film matrix with the inert gas;
• to reduce a ratio of precursor ligand to oxide from the thin film matrix.