Effect of process parameters on phase stability and metal-insulator transition of vanadium dioxide (VO2) thin films by pulsed laser deposition

Owing to remarkable thermochromic, electrochromic, and photochromic properties which arise from a first-order phase transition from insulator to metal at 68 degrees C, vanadium dioxide (VO2) has an enormous range of potential applications. However, due to such narrow thermodynamic stability, there is a major challenge surrounding selective phase deposition of vanadium dioxide thin films. Here, we present a report that establishes precise conditions for the deposition of three major polymorphs of VO2 by pulsed laser deposition. By a systematic study of the synergistic effects of the deposition conditions using a robust design of experiment (Taguchi design), we are able to deposit the VO2 (M1), VO2 (T), and VO2 (A) phases onto thermal oxide (Si/SiO2) substrates with remarkable precision. By electrically probing the temperature induced phase transformation from insulator to metal of each of these polymorphs, we find not only a strong dependence on the phase, but that the nature of the deposition conditions influences the magnitude and hysteresis width of the temperature cycle. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.