Functional Nanostructures for Gas Sensors

Sammanfattning: This research focuses on three main topics within the aims of FUNMAT, which are:Ohmic contacts to high-temperature chemical gas sensors.Studies of catalytic monolayers on active gate metal in SiC-based gas sensors.Investigating potential sensing properties of the nanoscale material MXene.Within the first research topic, we study the growth of Ohmic contacts to 4H-SiC for high temperature and corrosive environment applications, being a need in chemical gas sensors e.g. for automotive industry. For this purpose, common commercially-synthesized contacts are not suitable, due to either the presence of low-melting point elements or rapid oxidation. Improving the previously reported growth methods, designing durable oxygen-barrier capping layers, and synthesizing new contact-materials are our main focuses.For the second research topic, we investigate the improvement of the sensing performance of platinum-based sensing layers in silicon carbide field-effect gas sensors, which have many industrial applications. This project started with modification of field-effect-based metal oxide semiconductor CO sensors by the synthesis of one monolayer iron oxide on the platinum sensing layers of the sensors. Monolayer metal oxides have been reported to enhance the catalytic properties of platinum which is a promising result to be used in improving the performance of gas sensors.And finally, the third research topic covers studies of newly synthesized materials to be explored for any potential sensing property. Our focus is on metal carbide nano-sheets known as MXene phases and to study their  gas adsorption properties. Due to several uninvestigated features of newly synthesized materials, ab.initio. theoretical studies are of importance.