Interface engineering of Ta<sub>3</sub>N<sub>5</sub> thin film photoanode for highly efficient photoelectrochemical water splitting.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35132086.
- Also identified by DOI 10.1038/s41467-022-28415-4 and PMC identifier 8821563.
- 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
Interface engineering is a proven strategy to improve the efficiency of thin film semiconductor based solar energy conversion devices. Ta<sub>3</sub>N<sub>5</sub> thin film photoanode is a promising candidate for photoelectrochemical (PEC) water splitting. Yet, a concerted effort to engineer both the bottom and top interfaces of Ta<sub>3</sub>N<sub>5</sub> thin film photoanode is still lacking. Here, we employ n-type In:GaN and p-type Mg:GaN to modify the bottom and top interfaces of Ta<sub>3</sub>N<sub>5</sub> thin film photoanode, respectively. The obtained In:GaN/Ta<sub>3</sub>N<sub>5</sub>/Mg:GaN heterojunction photoanode shows enhanced bulk carrier separation capability and better injection efficiency at photoanode/electrolyte interface, which lead to a record-high applied bias photon-to-current efficiency of 3.46% for Ta<sub>3</sub>N<sub>5</sub>-based photoanode. Furthermore, the roles of the In:GaN and Mg:GaN layers are distinguished through mechanistic studies. While the In:GaN layer contributes mainly to the enhanced bulk charge separation efficiency, the Mg:GaN layer improves the surface charge inject efficiency. This work demonstrates the crucial role of proper interface engineering for thin film-based photoanode in achieving efficient PEC water splitting.