HAXPES-Guided Buried Interface Engineering Enables Low-Onset-Potential Ta<sub>3</sub>N<sub>5</sub> Photoanodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41543927.
- Also identified by DOI 10.1021/acs.nanolett.5c05408.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Efficient electron-hole extraction is essential for achieving high performance in Ta<sub>3</sub>N<sub>5</sub> photoanodes for solar water splitting. Prior studies on Ta<sub>3</sub>N<sub>5</sub> emphasized surface interfaces, while the buried junction governing carrier extraction and photovoltage generation remains less explored. Here, we introduce a buried junction engineering strategy experimentally validated by angle-resolved hard X-ray photoelectron spectroscopy (AR-HAXPES), which directly resolves the energy band alignment at buried interfaces. A phase-pure NbN conductive interlayer forming an atomically coherent, lattice-matched junction with Mg:Ta<sub>3</sub>N<sub>5</sub> is constructed. Depth-resolved AR-HAXPES reveals a 0.26 eV reduction in Schottky barrier height at the NbN/Mg:Ta<sub>3</sub>N<sub>5</sub> interface compared with a conventional mixed-phase Nb<sub><i>x</i></sub>N contact, confirming optimized Fermi level alignment and accelerated electron extraction. Consequently, the NbN/Mg:Ta<sub>3</sub>N<sub>5</sub> photoanode achieves a low onset potential of 0.38 V vs RHE and a record applied bias photon-to-current efficiency of 4.38%. This work establishes HAXPES-guided buried interface engineering as a powerful strategy for advancing photoelectrodes for solar fuel production.