In this study, a combinatorial AlN–TiN nanocolumn composite composition spread (library) was fabricated using reactive sputtering, and the formation of TixAl1–xN at the interface between AlN and TiN thickness gradients was investigated. Moreover, the intimate coupling between TixAl1–xN, AlN, and TiN, which enhanced the piezo-related properties of AlN, was analyzed. Location 1 [(1 − x)AlN − xTiN, 0 < x < 0.03] on the library exhibited superior piezotronic and piezophototronic effects because of the piezopotential modulation at the two ends of the nanocolumn. The location also exhibited excellent reliability and the highest piezophotodegradation coefficient k of approximately 7.5 × 10−3/min for all samples under study. The improved piezophotodegradation reaction was a result of the enhanced optical absorption, reduced recombination of photogenerated electron–hole pairs, and intimate coupling between TixAl1–xN, AlN, and TiN. Moreover, the applied bias photon-to-current efficiency of the piezophotoelectrochemical reaction at Location 1 was approximately 14 times higher than the efficiency of the photoelectrochemical (PEC) reaction under a bias of 0.5 V (versus Pt). The improvement was due to the favorable valence band position for water splitting and the enhanced piezophototronic effect. The study of the PEC reactions indicates the novel environmental sustainability of (1 − x)AlN − xTiN (0 < x < 0.03) on the library.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry