Étude du dopage de couches minces de VO2 déposées par ablation laser par des éléments légers (B et C)
Of all the materials that possess a metal to insulator transition, vanadium dioxide (VO2) has the transition temperature (TMIT ≈ 68°C) closest to room temperature. This phase transition is accompanied by an important variation in electrical resistivity (Δρ) and infrared transmission (ΔA). Thin films of VO2 have the potential to be used for a wide range of applications within electronic and optical devices. However, the usefulness of this material for these technologies would be greater if TMIT was closer to room temperature. Via doping, TMIT can be reduced and the most effective dopant amongst those that have been studied is W but this type of doping causes a reduction in Δρ. The search for a better dopant that could reduce TMIT while minimizing the degradation of the electrical properties is therefore of great importance. Boron and carbon are two elements that have been predicted by Density Functional Theory (DFT) to be excellent dopants to reduce the transition temperature of VO2. On another note, one synthesis technique that results in high quality of deposition is pulsed laser deposition. The goal of this master’s thesis has been to develop methods to deposit thin films of VO2 by pulsed laser deposition doped with certain elements, namely boron and carbon, and study the effect of their incorporation on the properties of the phase transition of these thin films.
VO2 Couche mince B C Phase transition Pulsed laser deposition Thin films Doping