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Study of the conduction mechanisms and interface defects in non-stoichiometric semiconductors with different morphologies

Grant number: 18/26550-0
Support type:Scholarships in Brazil - Doctorate
Effective date (Start): September 01, 2019
Effective date (End): July 31, 2021
Field of knowledge:Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
Principal Investigator:Miguel Ángel Ramírez Gil
Grantee:Pedro Paulo da Silva Ortega
Home Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil
Associated research grant:13/07296-2 - CDMF - Center for the Development of Functional Materials, AP.CEPID


Carbon monoxide, for being highly toxic and hard to detect by human beings, is responsible for thousands of deaths around the world annually, which can be avoided by the use of gas sensors. Therefore, this proposal aims to study the sensor properties of europium doped cerium dioxide matrices synthesized by the microwave assisted solvothermal method with different morphologies (cubes, polyhedrons, rods), from which sensor films will be fabricated with the help of an electronic deposition device based on piezoelectric actuators, aiming their applications in carbon monoxide devices. The materials obtained will have their structural and morphological properties characterized by x-ray diffraction, Raman spectroscopy, infrared spectroscopy, scanning electron microscopy, specific surface area and transmission electron microscopy. The sensor films previously deposited on alumina substrates with interdigitated platinum electrodes will be characterized by the most modern techniques at the atomic, structural, morphological and electrical levels, such as X-ray photoelectron spectroscopy, impedance spectroscopy, among others. The sensor film performance regarding its sensibility, response and recovery time, selectivity and work temperature will be evaluated in atmospheres of oxidizing and reducing gases in a sensor chamber developed and patented by the group (PI20150103953 - Argentina) with controlled temperature and atmospheres. Therefore, the experimental results will be correlated to the theoretical studies and it will allow a deep understanding of the connection between structure and properties, focusing on the optimization of the sensor material performance by means of the comprehension of the surface morphology, composition, defects and conduction mechanisms developed by the semiconductor material fabricated. (AU)