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Exploring novel donor-acceptor system: Spectroscopic insights, photostability, and performance evaluation inorganic solar cells
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Abstract:
Organic solar cells (OSCs) should demonstrate sufficient stability, scalability, and cost- effectiveness, beyond just high power conversion efficiency (PCE), for commercial viability. This PhD thesis delves into the photophysical properties and interactions of various donor- acceptor systems to enhance the efficiency and stability of OSCs. It provides insights into material selection and integration strategies to overcome photodegradation challenges, paving the way for the development of more efficient and stable organic solar cells. The introductory chapter offers a thorough understanding of the fundamental concepts. theoretical principles, and photostability in OSCs. It includes background information. photophysical explanations, and literature reviews, enabling readers to understand the design of efficient and stable OSCs. The second chapter details he experimental techniques employed throughout this study. In the first results chapter, the study explores a novel combination of Rhodamine B (RhB) as a donor and graphene as an acceptor. Absorbance measurements confirm the formation of a RhB-graphene complex, and fluorescence quenching studies demonstrate significant efficiency after accounting for inner filter effect of graphene. Stern-Volmer analysis suggests that RhB-graphene is a promising alternative for photovoltaic applications due to its potential for efficient photoinduced electron transfer. The second results chapter examines the photostability of two donor materials, PTB7-Th and PBDB-T, in neat and blend films with PC70BM. UV-Vis spectroscopy and molecular probe studies reveal that PTB7-Th is more susceptible to photodegradation and exhibits higher singlet oxygen ('O2) generation compared to PBDB-T. FTIR analysis indicates significant chemical and structural changes in PTB7-Th films after exposure to light and ox ygen. The observed correlation between photochemical stability of the polymers and singlet ox ygen generations may be linked to their molecular structures and crystallinity, aiding in the identification of suitable materials for long-term operation. Considering the challenges posed by photodegradation, the third results chapter examines the integration of RhB dye as an additional donor to enhance the efficiency and stability of ternary OSCs. The inclusion of RhB enhances the internal quantum efficiency and blend morphology of the active layer, leading to improved charge generation and, consequently, a higher PCE. Photoluminescence studies confirm Förster resonance energy ransfer (FRET) from RhB to PTB7-Th contributing to the enhanced performance in the ternary device. The final chapter summarizes k ey findings, ighlighting significant advancement and suggesting future research directions based on the current study results.
Description:
xx, 162 pages : color illustrations ; 30 cm | A thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Applied Physics | Thesis is also available in CD and is not for loan or reference use | Thesis (Doctor of Philosophy) – Universiti Brunei Darussalam, 2024 | includes bibliographical references pages 158-160.
Date:
2024
Authors:
Syed Abbas Raza
Publisher:
Universiti Brunei Darussalam
Citation:
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Keywords:
Dissertation. Universiti Brunei Darussalam , Spectrum analysis , Semiconductors -- optical properties
