Dr. Kebra Ward

MCLA Physics Department

Research

My research explores how light interacts with matter, particularly in organic molecular crystals such as rubrene. When rubrene absorbs light, it creates a photoexcited state that can move from molecule to molecule through the crystal. Understanding how this energy moves is important for developing organic electronic and optoelectronic materials used in technologies like solar panels and flexible displays.

In my lab at MCLA, students and I use ultrafast laser techniques to study how these excitations form, share energy, and evolve over time. Using a degenerate four-wave mixing setup, we send short laser pulses into molecular crystals or liquid solutions to observe how energy transfers between molecules. This approach lets us track not only the bright “singlet” states that emit light, but also the elusive “triplet” states that do not. By detecting subtle changes in how the crystal bends or absorbs light, we can map how energy moves through the material without relying on emitted light.

In 2022, I was awarded a Fulbright U.S. Scholar Fellowship to teach and conduct research in South Africa at Nelson Mandela University. There, I worked with local faculty to study how evidence-based, interactive teaching methods, such as Peer Instruction, affect student learning in large introductory physics courses. Our research, published in Physics Education (2025), found that while discussion-based learning improves understanding, its success depends strongly on student engagement and reasoning skills. The experience deepened my commitment to creating inclusive, hands-on learning environments that help all students build confidence and scientific reasoning ability.

At MCLA, I continue to combine my passion for experimental optics and physics education research. My students gain experience with advanced laser systems while also learning how scientists study the process of learning itself. I believe that doing physics, both in the lab and in the classroom, is the best way to understand it.

Publications

Effectiveness of peer instruction in the South African college-level physics classroom, Lindsay Westraadt and Kebra Ward, Phys. Educ. 60 045031 (2025)

Routes to singlet exciton fission in rubrene crystals and amorphous films, Drew M. Finton, Eric A. Wolf, Vincent S. Zoutenbier, Kebra A. Ward, and Ivan Biaggio, AIP Advances, 9, 095027 (2019)

Nanosecond pump and probe observation of bimolecular exciton effects in rubrene single crystals, Kebra A. Ward, Brittany R. Richman, and Ivan Biaggio, Appl. Phys. Lett. 106, 223302 (2015) 

The Manga Guide to the Universe, (as Technical Reviewer) Kenji Ishikawa and Kiyoshi Kawabata, No Starch Press (2011)

Talks & Presentations

REUs and Internships Panel Member, Conference for Undergraduate Women in Physics (CUWiP), University of Massachusetts, Amherst (2019)

Nanosecond Pump & Probe Observation of Bimolecular Exciton Effects in Rubrene Single Crystals, Materials Research Society Fall Meeting (2014)

Exciton Dynamics in the Rubrene Single Crystal, Frontiers in Optics (2013)