As part of its commitment to advancing scientific research and promoting specialized studies in materials physics and renewable energy technologies, Mohammed Hadi Mahdi Ahmed, a master’s student in the Department of Physics at the College of Education for Pure Sciences (Ibn Al-Haitham), defended his thesis entitled:
“A Theoretical Study of the Charge-Transfer Reaction Rate in Indoline Dye in Contact with Titanium Dioxide (TiO₂) Semiconductor,” supervised by Professor Hadi Jabbar Mujeebal.
The thesis presents a theoretical investigation of electron-transfer mechanisms in dye-sensitized solar cells (DSSCs) based on the indoline D102 dye and titanium dioxide (TiO₂) semiconductor. The study employs quantum transport theory to analyze charge-transfer processes between excited dye molecules and the semiconductor. Its primary objective is to evaluate how the physical and chemical properties of the surrounding medium influence the probability and rate of electron transfer, thereby contributing to a better understanding of the factors governing the performance of these solar energy systems.
The research adopts a semiclassical theoretical approach to calculate the reorganization energy and employs MATLAB to simulate electron-transfer behavior and examine the effects of several parameters, including reorganization energy, electronic coupling strength, and charge-carrier concentration. Six different solvents were investigated: dimethoxyethane, dichloromethane, tert-butyl alcohol, 1-butanol, ethanol, and methanol, to assess how the properties of the surrounding medium affect charge-transfer processes.
The theoretical results indicate that the probability of electron transfer is influenced by the nature of the solvent, reorganization energy, electronic coupling strength, and charge-carrier concentration. Under the investigated conditions, the probability of electron transfer increased with increasing electronic coupling strength and carrier concentration, reaching a reported maximum at a concentration of (7 \times 10^{18}) cm⁻³ and an electronic coupling strength of (1.244 \times 10^{-6}) eV. The findings also revealed variations in the system’s response depending on the solvent employed, highlighting the importance of the physical properties of the surrounding medium in understanding charge-transfer behavior in dye-sensitized solar cells.
The significance of this research lies in its contribution to the theoretical understanding of charge-transfer processes in semiconductor-based solar energy systems. Its findings may provide a foundation for future investigations aimed at improving material properties and interfacial interactions in solar cells, thereby supporting scientific research into renewable energy technologies.
The examination committee comprised Professor Samira Ahmed Ibrahim, Chair; Assistant Professor Rawnaq Qais Ghadban, Member; Assistant Professor Nisan Saud Oraibi, Member; and Professor Hadi Jabbar Mujeebal, Member and Supervisor.
The research aligns with several United Nations Sustainable Development Goals, particularly:
SDG 7: Affordable and Clean Energy — by advancing theoretical research into electron-transfer mechanisms in solar cells, potentially contributing to the development of solar energy conversion technologies.
SDG 9: Industry, Innovation and Infrastructure — by promoting scientific research and innovation in semiconductor materials and solar cell technologies.
SDG 13: Climate Action — by supporting scientific knowledge relevant to the development of renewable energy technologies that may help reduce reliance on emission-intensive energy sources.
This thesis defense reflects the College’s commitment to fostering specialized scientific research and advancing academic studies that connect theoretical physics with contemporary technological applications, particularly in renewable energy and advanced materials.
