Abstract:

The influence of copper-phthalocyanine (CuPc) hole-injection layer on the capacitance-voltage (C-V) characteristic performance of ITO/CuPc/PVK/Rhodamine B/Pb devices was investigated. The thickness of the CuPc layer was varied form 5 nm to 50 nm. The thin films were deposited on the PVK layer by thermal vacuum deposition at 1.0 × 10- 5 torr using MiniLab 080 system. The thicknesses were measured using using FILMETRICS F20-UVX thin-film analyzer. It was found that as the thickness of CuPc layer decreases the transition voltage (VT) and built-in voltage (Vbi) decrease except for a thickness 5 nm, which shows negative differential resistance (NDR).

Mohammed completed his Bachelor’s degree in Physics at the Islamic University of Gaza-Palestine in 2011. Then he followed a Master’s degree in Physics (with thesis) at the same university, graduating in 2015 master’s research focused on “The Influence of Copper-phthalocyanine Layer, Heat Treatment, and Electric Field on the Performance of Poly(9-Vinylcarbazole)/Rhodamine B/Pb OLEDs,” emphasizing thin-film preparation and optoelectronic device characterization. During his early academic career, he worked as a Teaching Assistant at both the Islamic University of Gaza (2011–2015) and the University College of Applied Science (2016–2022). He also served as a Research Assistant at the Renewable Energy Center, Islamic University of Gaza (2012–2014).

 

The innermost stable circular orbit (ISCO) marks the inner edge of a thin accretion disk around a black hole when its luminosity is low compared to the Eddington limit. We study the equatorial circular motion of charged test particles around a Schwarzschild black hole immersed in a dipole magnetic field generated by an equatorial current loop. We study how the ISCO radius depends on two key parameters: magnetic coupling and loop radius. I will show in this seminar how the sign of the magnetic interaction relative to the particle’s angular momentum divides the motion into two distinct regimes, strongly affects the ISCO location, and can lead to gaps with no stable circular orbits. I will also discuss the implications for low density regions in real accretion disks.

Fatimah H. Alhazmi is an M.Sc. Physics student at KFUPM. She had previously worked and interned at KAUST on high-order numerical methods for large-scale simulations with the Advanced Algorithms and Numerical Analysis Laboratory. She is an Affiliate Researcher with the Wolfram Institute and a Qimam Fellow (2023).

All faculty, researchers and students are invited to attend.