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Author: Boris Iulia Degree: doctor of Physics Speciality:  01.04.10 - Semiconductors physics and engineering Year: 2016 Scientific adviser: Vladimir Brînzari doctor, associate professor (docent) Institution: Moldova State University

Status The thesis was presented on the 21 December, 2015 Approved by NCAA on the 25 February, 2016 Abstract – 0.72 Mb / in romanian – 0.74 Mb / in russian Thesis CZU 621.315.592.3 2.55 Mb / in russian 129 pages

Keywords

Summary

The thesis consists of Introduction, 4 Chapters, General conclusions and recommendations, 170 References, 129 Pages, 55 Figures, 3 Tables. The results presented in the thesis are published in 44 scientific works.

Domain of study: gas sensors.

Goal and objectives: comprehensive and comparative research of In2O3- and SnO2-based binary oxides doped by additives of different type and valence (from metals to non-metals) and establishment of the additive role on their gas sensing properties on an example of sol-gel and thin-film technologies.

Scientific novelty and originality: for the first time it was carried out the comprehensive and comparative study of In2O3-based one-electrode gas sensors prototypes for the wide range of doping additives; it was found the effect of mutual nanoclusters formation of both base oxide and additive oxides for SnO2 doped by Co, Cu, Fe, Ni at doping levels exceeding the limit volume solubility.

Important scientific problem solved: it was demonstrated the possibility of gas sensing properties control for metal oxides based on In2O3 ceramics and SnO2 thin films through their doping by additives of different type and it was established the structural and the sensor activity of these additives.

Theoretical importance: it was clarified contribution of adsorption and electronic mechanisms to gas sensing improvement or suppression at doping, their connection with the transitions from the volume solubility to the formation of a separate phase of the additive oxides both for In2O3 and SnO2.

Practical significance: the prototypes of one-electrode and thin-film sensors based on In2O3 and SnO2 with improved operational characteristics, such as increased gas sensitivity (In2O3: Ga, P, Cu, Zn), (SnO2: Cu, Co), increased selectivity (In2O3: Cu, P, Mn), increased stability (In2O3: Ga, Al, Zn, Fe), low response recovery times, low sensitivity to humidity(In2O3: Ga, Al) were proposed.

Oficial Reviewers

• Dormidont Şerban
  doctor habilitat, Institute of Applied Physics of the
• Viorel Trofim
  doctor habilitat, professor, Technical University of Moldova
• KOROTCHENKOV Ghenadii
  doctor habilitat în științe fizico-matematice, profesor universitar, Corea de Sud

Council's Members

• Petru Gaşin, president
  doctor habilitat, professor, Moldova State University
• Valentina Nicorici , secretary
  doctor, associate professor (docent), Moldova State University
• Leonid Culiuc, member
  doctor habilitat, professor, Institute of Applied Physics of the
• Mihail Caraman, member
  doctor habilitat, professor, Moldova State University
• Emil Rusu, member
  doctor habilitat, associate professor (docent), Institute of the Electronic Engineering and Nanotechnologies
• Oleg Lupan , member
  doctor habilitat, associate professor (docent)

 Theses