Chemical state analysis of reactively sputtered zinc vanadium nitride: The Auger parameter as a tool in materials design

Photoelectron spectroscopy is an important tool for the development of new materials. However, especially for nitride semiconductors, the formation of surface oxides, surface band bending as well as the lack of a suitable charge reference often prevent a robust analysis. Here, we perform a comprehensive chemical state analysis of the Zn-V-N phase space using the Auger parameter concept, which is less sensitive to such uncertainties. Phase-pure Zn2VN3, VN, and Zn3N2 samples are analyzed using XPS/HAXPES after transfer in inert-gas atmosphere. In addition, high-throughput chemical state analysis is performed on combinatorial Zn1-xVxN thin film libraries. The evolution of the Zn Auger parameter in Zn1-xVxN is consistent with previous mapping of the structural and functional properties. Strikingly, the study reveals a narrower stability range of wurtzite Zn1-xVxN than our previous high-throughput XRD screening, highlighting the sensitivity of the measurement approach. The procedures applied here are transferable to many other material systems and could be particularly useful for the high-throughput development of materials with low crystallinity where insights from XRD screenings are limited.