Crystalline vanadium nitride ultra-thin films obtained at room temperature by pulsed laser deposition

In this work the synthesis of vanadium nitride ultra-thin films by means of pulsed laser deposition technique is reported. The solid target used for laser ablation was prepared from vanadium nitride powder synthesised by sol–gel of V2O5 followed by temperature programmed reduction with ammonia. The films deposition was performed at room temperature and 500 °C on glass or Si substrates and the films were characterised by different techniques, i.e., Scanning and Transmission Electron Microscopy, X-Ray Diffraction, Atomic Force Microscopy and X-ray Photoelectron Spectroscopy. As a function of the deposition conditions, the films present different thicknesses, reveal a homogenous dense to slightly porous morphology and are highly crystalline. As determined by X-ray Photoelectron Spectroscopy analyses the VN films are nitrogen deficient due to the formation of an oxide layer on their surface. The possibility of depositing crystalline VN ultra-thin films at room temperature using a VN target is of great importance for several possible applications where low temperature substrates are employed.