StatusThe thesis was presented on the 24 February, 2022
Approved by NCAA on the 1 July, 2022
Abstract– 2.07 Mb / in romanian
7.09 Mb /
The structure of the thesis: The thesis consists of introduction, 5 chapters, general conclusions and recommendations, 146 basic text pages, 243 bibliographic sources, 16 tables, 93 figures and 4 annexes. The obtained results are published in 30 scientific papers: 7 articles (2 of wich are published in international journals with IF) and 23 abstracts at international scientific conferences.
Field of research: organic materials and structures for photovoltaics, Physics and Technology of Materials.
The goal of the thesis: The development and the optimization of the technology of ZnPc based thin films synthesis from chemical solutions, by spin coating and drop casting methods, as well as the study of structural and optical properties of the obtained layers for its implementation in the production of photovoltaic devices. The objectives of the thesis: The development of the protocol of solubilization for ZnPc and PTDCI; optimization of the synthesis and doping regimes of the thin films in order to control their physical properties for photovoltaic applications; the investigation of the correlations between microstructure and optical properties; the optimization of the technological regime for fabrication of the photovoltaic devices.
Novelty and scientific originality: The development and the optimization of ZnPc and PTCDI thin films synthesis regimes from chemical solution, as well as in situ iodine doping regimes of these layers; synthesis for the first time, from solutions, of photovoltaic devices based on ITO/PEDOT:PSS/ ZnPc:I2/Al Schottky diode with the value of open circuit voltage 1.03 V, higher than in the case of devices obtained by thermal evaporation in vacuum; The obtaining for the first time of the photovoltaic devices based on ITO/PEDOT:PSS/ZnPc:I2:PTCDI/Al bulk heterojunction with conversion efficiency 2.4%; elucidation of the interaction mechanisms between the solvent (FA), the active substances (ZnPc and PTCDI) and the dopant (I2) based on the complex study of morphological, structural, vibrational and optical properties; establishing of the transport mechanisms of the electrical carriers through the developed devices at the application of the electric field and light.
Scientific problem solved in this doctoral thesis is the development of manufacturing technology with low production costs of organic solar cells based on ZnPc and ZnPc: PTCDI, the understanding of the physical principles of operation and the finding of solutions to increase the efficiency of solar energy conversion of the devices. The theoretical significance of the thesis consists in elucidating the physical processes which allow effective control over nucleation and growth of thin layers from chemical solutions, the controlled formation of the interface of structures based on ZnPc Schottky diode and ZnPc:PTCDI bulk heterojunction, and clarifying the nuances of electric charge transfer process from the interface.
The applicative value of the thesis consists in the elaboration and optimization of the technology of the preparation of ZnPc Schottky diode and ZnPc: PTCDI bulk heterojunction devices with a higher conversion efficiency compared to the efficiency of the devices obtained by thermal evaporation in high vacuum.
Implementation of the results: The obtained scientific results can be implemented in the educational process at the Research and Innovation Institute of the State University of Moldova.