Substantial lifetime enhancement for Si-based photoanodes enabled by amorphous TiO<sub>2</sub> coating with improved stoichiometry.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37015923.
- Also identified by DOI 10.1038/s41467-023-37154-z and PMC identifier 10073107.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Amorphous titanium dioxide (TiO<sub>2</sub>) film coating by atomic layer deposition (ALD) is a promising strategy to extend the photoelectrode lifetime to meet the industrial standard for solar fuel generation. To realize this promise, the essential structure-property relationship that dictates the protection lifetime needs to be uncovered. In this work, we reveal that in addition to the imbedded crystalline phase, the presence of residual chlorine (Cl) ligands is detrimental to the silicon (Si) photoanode lifetime. We further demonstrate that post-ALD in-situ water treatment can effectively decouple the ALD reaction completeness from crystallization. The as-processed TiO<sub>2</sub> film has a much lower residual Cl concentration and thus an improved film stoichiometry, while its uniform amorphous phase is well preserved. As a result, the protected Si photoanode exhibits a substantially improved lifetime to ~600 h at a photocurrent density of more than 30 mA/cm<sup>2</sup>. This study demonstrates a significant advancement toward sustainable hydrogen generation.