Abstract

This thesis demonstrates light-assisted gas sensing by low-dimensional structures (graphene and two-dimensional metal chalcogenides). Studies on the prototype graphene-based resistive sensors show that the configuration of the device and the used substrate affect sensing properties. The sensors with Schottky diode configuration with graphene deposited directly on silicon exhibited high sensitivity and stability at lower voltage bias compared to graphene transistors. This confirms the possibility of adjusting sensor fabrication toward low-power consumption devices. Furthermore, the thesis demonstrates the solution-based printing of gas-sensitive layers from two-dimensional flakes as an alternative to more complex deposition techniques. The subsequent studies on molybdenum disulfide and zirconium trisulfide showed that light-enhanced molecular detection is potentially driven by similar mechanisms for materials of similar structure. The comparison between the sensing performance of the selected materials is a step toward optimizing detection systems as well as understanding gas sensing mechanisms.

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