Metal oxide nanostructures: synthesis, characterization, optical properties and their applications as gas sensors

Research on nanostructurred metal oxides (MOXs) represents a fertile path for the potentiality these materials have in several application. Particularly interesting is the gas sensing field, often based on the use of semiconductor nature of MOX and their intrinsic structural properties, such as crystallinity and presence of defect states, that make them appealing research material both for improving existing devices and for novel applicative systems. In this direction is setting forth the study of nanostructured MOX properties for the development of optochemical gas sensors, field in which my Ph.D. work is contextualized. My research project consisted in the morphological, structural and optical characterization of nanostructured MOX (TiO2 and ZnO) thin films in view of application in optical gas sensing. Material ablation and deposition is obtained by pulsed laser ablation (PLD) technique in the nanosecond and femtosecond pulse regime wicth characterization performed by means of scanning electron microscopy (SEM), X-ray diffractometry (XRD), continuous wave (CWPL) and time resolved (TRPL) photoluminescence, excitation photoluminescence (PLE) and absorption spectrophotometry (visible region and IR). Optical responses (luminescence) of materials are studied varying conditions of the ambient gas environment in interaction with them: By comparison of materials different stimulus and gas species responses, we will quantitatively screen out pros and cons of nanostructured metal oxide applications as optical sensors.