ICTP-EAIFR is pleased to welcome Dr. Georgies Alene Asres, Associate Professor at the Center for Materials Engineering, Addis Ababa Institute of Technology, Addis Ababa University, Ethiopia, who will deliver a hybrid seminar on September 4, 2024 at 4:00 p.m. (Kigali time).

Physical Venue: conference room
On-line: Please Register in advance for this meeting here.

Title: Electronic structure of strain-tunable Janus WSSe–ZnO heterostructures from first principles.

Abstract:
The electronic properties of 2D materials, such as monolayer transition metal dichalcogenides (TMDs), can be tuned through environmental factors and external fields. Stacking different 2D materials into van der Waals (vdW) heterostructures provides a way to further fine-tune and enhance their electronic properties. In this study, we employ density functional theory (DFT) calculations to analyze the structure and electronic characteristics of a vdW heterostructure composed of Janus monolayer WSSe and monolayer ZnO, both exhibiting out-of-plane dipole moments. We examine how alignment, biaxial and uniaxial strain, orientation, and electric fields affect the dipole moments and band edge energies of this heterostructure. Our findings reveal that the ZnO monolayer's out-of-plane dipole moment is highly responsive to strain, allowing for significant tuning of the heterostructure's band edge energies across a range of experimentally relevant strains. This approach of using strain-tunable 2D materials to manage band offsets and alignments is a versatile strategy that could benefit various applications, including clean energy and photocatalytic technologies.

Biography:
Dr. Georgies Alene Asres is an associate professor at the Center for Materials Engineering in Addis Ababa Institute of Technology, Addis Ababa University, Ethiopia. He has a BSc in Applied Physics from Arba Minch University, Ethiopia (2003-2006), and double Master degree in Functional Advanced Materials Engineering (Augsburg University), Germany and (Grenoble Institute of Technology) France (2008-2010), and a Doctor of Science (Technology) in Electrical Engineering (Electronics Materials and Devices) from Oulu University, Finland (2014-2018). He has also worked as a graduate assistant (2006-2008) and a lecturer (2010-2014) at Arba Minch University at department of physics, Ethiopia. His research interests include 2D materials and their heterostructures for photocatalytic water splitting and photovoltaics using DFT, synthesis and characterization of nanomaterials, and energy efficiency. He has published several papers in international journals and conferences and received grants for his research. He is also actively involved in teaching, mentoring, and supervising graduate students at Addis Ababa Institute of Technology, Addis Ababa University. He is also the head of center for Materials Engineering.