Contact : Clémence Badie
In the context of energy transition, electrochemical reactions such as electrolysis are in high interest as they generate “green” H2 or NH3 for instance. Noble metals are state of the art compunds but they are critical elements. Alternative materials are required and transitional metal compounds are now investigated. Looking for less expensive and Earth-abundant compounds is one leverage point ; another one is to optimize the material mass/efficiency ratio. Therefore, we are developing transitional metal oxynitrides (TMONs) and nitrides (TMNs), mono or pluri-elementary, thin films using Atomic layer deposition (ALD). This technique allows precise thickness control even on complex substrate thanks to the auto-limited growth of the layer on a substrate. This is achieved by the sequential injections of the precursors in the reactor, spaced by purging durations, avoiding precursors to react with each other, as depicted in the figure below. The objective is to study the relationship between the ALD-layer characteristics and their electrochemical properties.
Figure : Schemes of an ALD cycle (left) and an electrochemical cell with a magnification on the working electrode (right) : ALD nitride layer mono and pluri-elemental for hydrogen evolution reaction (HER).