Zijun XU soutiendra sa thèse intitulé :
" Dye and Electroactive Monomer Conjugates for Hole Transfer Material in Solid-State Dye-Sensitized Solar Cells " le 05 Mai 2021 à 14h en visio conférence accessibkle à cette adresse :
https://u-paris.zoom.us/j/3432267488?pwd=MXdreFFuNWM1cDlsVWpOREZUbGpVdz09
ID de réunion : 343 226 7488
Code secret : yT9PsP

Résumé :
The objective of this work is to develop solid-state dye sensitized solar cells (ss-DSSCs) in order to optimize the interfacial charge transfer within the solar cell. Despite of the broad use of liquid electrolyte, stability issues arose from solvent evaporation as well as liquid leakage have limited the large-scale production and commercialization of dye sensitized solar cells (DSSCs). The replacement of liquid electrolyte with solid hole transport materials (HTMs) is indispensable for long-term developments of devices. Conducting polymers is chosen in this work as HTM for its higher hole conductivity, good stability and facile preparation. Part of the newly designed dye molecule (otherwise called sensitizer), the electroactive monomer carbazole is used as
initiator for co-polymerization with bis-(3,4 ethylenedioxythiophene) (bis-EDOT) as precursor in the in-situ photoelectrochemical polymerization (PEP) process, to ensure the covalent link between the light active center and the generated co-polymer, which serves as HTM. The interface between the dye and HTM is naturally removed as a result. Moreover, the blocking effect of alkyl chain in terms of the performances of ss-DSSCs has also been investigated by altering the molecular structure of dye.
The thesis is composed of five chapters. Chapter 1 gives a general context of photovoltaic solar cells as an introductory chapter. Chapter 2 focuses on the DSSCs including the components, working principle and characterization techniques of DSSCs. Chapter 3 begins by laying out different types of sensitizers and looks at how to design new organic sensitizer which could be covalently linked to the HTM. Chapter 4 presents the results of DSSCs fabricated with originally designed sensitizer. Chapter 5 ties up theoretical and empirical strands with a discussion of the implication of findings to future study in the area.

Keywords: Solid-State Dye-Sensitized Solar Cells, in-situ Photo-Electrochemical Polymerization, donor-linker-acceptor organic dyes, covalent link, hole transporting material, conducting polymer

Jury de thèse:

Directeur de thèse :
François Maurel, Professeur, Université de Paris
Co-Directrice de thèse :
Chang-Zhi Dong, Professeur, Université de Paris
Rapporteurs :
David Kreher, Professeur, Université de Versailles Saint-Quentin-en-Yvelines
Yu Pei, Chargé de Recherche, Université Paris-Saclay
Examinatrice :
Corinne Lagrost, Directrice de Recherche, Université de Rennes 1
Claire Mangeney, Professeure, Université de Paris
Invité:
Mohamed Jouini, Professeur, Université de Paris