Beyond electrochromic properties of sputtered WO3 thin films

State of the art of inorganic electrochromic materials, WO₃ thin films switch from colorless to blue state under an applied potential. The applications of electrochromic devices, ECDs, are multifold from smart windows in cars, rearview mirrors and protective eyewear as transmission or reflection properties in the visible or infrared range are concerned. In our group, we recently reported a careful optimization of the deposition conditions of WO₃ thin films leading to unexpected memory effect [1]. Aging of the Li_xWO₃ reduced films leads to crystallization whose origin needs to be clarified. Beyond this EC property, the morphology, composition and structure of the films reveal to be key features in various domains related to ionic conductions. The aim of the current internship is, by combining several characterizations tools, to move forward towards in-depth understanding of unexpected electrochemical and/or optical behavior.  To achieve this goal, the candidate will have to perform thin films deposition, physico-chemical characterizations electrochemical and optical ones.

[1] B. Faceira et al., Towards the Prediction of Electrochromic Properties of WO₃ Films: Combination of Experimental and Machine Learning Approaches, J. Phys. Chem. Lett.  2022 13, 8111 – 8115.