SEMINAR
Fabrication and characterization of natural dye-sensitized solar cells using an efficient natural sensitizer derived from bay leaves.
Speaker:
Ms. IBTIHAL ELTAHER
Regular PhD Student
Date: Monday, December 8th, 2025
Time: 11:00 to 11:15 a.m.
Location: Bldg. 6/Room 125
Abstract:
This work investigates the development and analysis of natural dye-sensitized solar cells (NDSSCs) utilizing a chlorophyll-rich extract derived from Laurus nobilis (bay leaves) as a sustainable and environmentally friendly sensitizer. The dye extraction was performed using a methanol-based maceration method optimized to achieve maximum chlorophyll yield and stable pigment retention. NDSSCs were constructed on both fluorine-doped tin oxide (FTO) and indium-doped tin oxide (ITO) substrates to evaluate performance based on substrate type. Comprehensive characterization—utilizing UV–Vis, FTIR, XRD and J–V analysis validated the strong attachment of chlorophyll molecules to the TiO₂ surface. The FTO-based cell demonstrated superior photovoltaic characteristics, with a short-circuit current density (Jsc) of 0.528 mA cm⁻², an open-circuit voltage (Voc) of 0.615 V, a fill factor (FF) of 69.9%, and an overall efficiency (η) of 0.227%, surpassing that of the ITO-based cell. Electrochemical impedance analysis indicated improved recombination resistance and extended electron lifetime for the bay leaf dye device compared to the N3 reference cell. These results highlight the potential of Laurus nobilis extract as a viable, cost-effective, and eco-friendly sensitizer for solar energy technologies.
SEMINAR
Achieving Ultra-Low Temperature Using Light
Speaker:
Mr. FAIZ KHAN
Regular PhD Student
Date: Monday, December 8th, 2025
Time: 11:20 to 11:35 a.m.
Location: Bldg. 6/Room 125
Abstract:
Laser cooling has revolutionized the field of atomic physics by enabling the manipulation of neutral atoms and ions at temperatures approaching absolute zero. This seminar presents an overview of the fundamental principles, key mechanisms, and modern advancements in laser cooling techniques. Beginning with the classical concept of cooling as a reduction in particle velocities, I will explore the pioneering proposals of Hänsch and Schawlow, which laid the foundation for Doppler cooling. I will then discuss sub-Doppler methods such as Sisyphus cooling, which exploit polarization gradients to reach temperatures below the Doppler limit. I will also go over some advanced approaches including sideband cooling in trapped ions and cavity-mediated cooling in optical resonators to highlight how quantum mechanical effects can be exploited to control the motion of trapped particles and achieve ultra-low temperature. Together, these techniques illustrate how simple ideas of light-matter interactions lead to produce some of the coldest systems.
SEMINAR
Unleaded Alloy
Speaker:
Ms. HALAH MANJAD
Regular Master’s Student
Date: Monday, December 8th, 2025
Time: 11:40 to 11:55 a.m.
Location: Bldg. 6/Room 125
Abstract:
Discover how safer, lead free materials can protect us from harmful radiation in hospitals, industry, and everyday environments. This seminar introduces the basics of ionizing radiation and how it interacts with matter, then shows how modern computational tools are used to design Tin–Silver–Copper (Sn–Ag–Cu) alloys as promising new shielding materials to replace toxic lead.
All faculty, researchers and students are invited to attend.