Tham wins undergraduate award for Beckman Image Contest

8/6/2020

Beckman Institute

Rachel Tham, the Minjoo Larry Lee Group
Rachel Tham, the Minjoo Larry Lee Group

Scientists at the Beckman Institute for Advanced Science and Technology recently showed off their research through Beckman Research Image Contest. This year, the contest features four winners in the following categories: undergraduate students, graduate students, postdoctoral researcher, and faculty. The four framed images are being featured in the Beckman director’s conference room. Last year’s winning images will be hung throughout the Beckman’s halls. Materials Science and Engineering undergraduate Rachel Tham who works under Illinois ECE Associate Professor Minjoo Lawrence Lee was one of the four winners, representing the undergraduate category.  The following is her winning submission:

Multijunction solar cells could significantly increase the efficiency of solar power. However, lattice mismatch between the device layers can lead to defects called threading dislocations that decrease their efficiency. Tham's research, conducted with graduate student Ryan Hool, works to better understand why and how these dislocations occur to make multijunction solar cells more efficient.

Rachel Tham's winning submission
Rachel Tham's winning submission

This image is a Nomarski (also called differential interference contrast) image of a beryllium-doped gallium phosphide (GaP) on GaP sample, after defect selective etching, and it was imaged with the Beckman Institute's inspection microscope at 50 times magnification. DSE reveals the location of threading dislocations as etch pits in the sample, and the number of etch pits present can then be used to calculate the sample's threading dislocation density.

“Researchers at the Beckman Institute use our state-of-the-art tools to work together across disciplines and break new barriers,” said Jeff Moore, the director of the Beckman Institute and an Ikenberry Endowed Chair in the Department of Chemistry. “These images show that research is not only important, but also visually beautiful. I continue to be amazed and inspired by the entries in the Beckman Research Image Contest.”

 

Read about the other winners on the Beckman site.