Assistant Beamline Scientist Grace Luo is facilitating next-generation science at the Advanced Photon Source

Light-emitting diodes (LEDs) are energy-efficient light sources that can last up to 25 times longer than standard incandescent lighting. They’re extremely versatile, which makes them ideal for a variety of applications. As good as LEDs are now, Yanqi ​“Grace” Luo is helping to make them better.

Luo is an assistant beamline scientist at the U.S. Department of Energy’s (DOE) Argonne National Laboratory. Luo works in the Advanced Photon Source (APS), a DOE Office of Science user facility. She collaborates with APS engineers to build experiment instrumentation. These instruments must be able to image samples, including materials for LEDs, under varying conditions — heating, illumination or applied voltage — to see how atoms move or how materials change.

“I’m looking forward to seeing the new science that’s possible now with the upgraded light source. If we can detect smaller metal impurities and other subtle defects that affect device performance, we can make more powerful technology.” — Grace Luo, assistant beamline scientist at the APS

“The goal is to understand a material’s response to external stimuli,” she said. ​“If we can understand and mitigate those responses, we can improve the robustness and performance of devices.”

Like the scientists she supports at the beamline, Luo is driven by curiosity.

“As a really young undergraduate, I started to probe deeper into how things work,” she said. ​“That’s what inspired me to do my Ph.D.”

Luo also enjoys the hands-on nature of science. She did her undergraduate studies at California Polytechnic State University, which is known for its slogan, ​“Learn by doing.”

In 2015, she came to the APS to perform her doctoral research, using synchrotron X‑rays to study photovoltaic and quantum devices. She was very impressed by the APS as well as Argonne.

When offered a job at the APS, Luo eagerly accepted. Ever since then, she’s considered Argonne her second home.

“Argonne has a highly collaborative culture,” she said. ​“You’re always engaging with other scientists, technicians and engineers. If you get stuck, there’s always someone who can help you get unstuck.”

Supporting users and experiments

Luo also collaborates with domestic and international user teams to set up their experiments at beamline 2-ID.

“One group I helped was studying light‑induced ion migration,” she said. ​“The first visit produced limited results due to setup issues. We had trouble making sure the light was actually shining on the spot they were scanning. After iterative improvements and a return visit, the team observed ions moving as expected, which later led to publications.”

Argonne accelerates the science and technology that drive U.S. prosperity and security. Argonne staff are thinkers, builders, problem-solvers and caretakers — every person and every role contributes to the laboratory’s impact on the world.

Luo believes that teamwork, a Core Value at Argonne, is a key ingredient for good science.

“It’s the combination of support and challenge at Argonne that fosters scientific excellence,” she said. ​“Rather than uncritical agreement, the people here provide critiques and suggestions that help everyone produce at our best.”

Using AI and brighter X-rays to expand discovery

For her own research, Luo is starting to incorporate machine learning and large language model artificial intelligence (AI) efforts, in collaboration with computational scientist Ming Du, to accelerate discovery.

“AI can help see the big picture and also pinpoint what aspects we should study next,” she explained.

The APS recently underwent a major upgrade that excites the assistant beamline scientist.

“Research teams who come to the APS now have brighter X-rays to use for their experiments,” she said. ​“Even more importantly, at 2-ID, we have increased the working distance between the lens and the sample. This opens the door for us to do some types of experiments we couldn’t do before.”

She explained that the extra space allows scientists to include more equipment around a sample. The ability to have additional equipment allows for new measurement modalities.

“I’m looking forward to seeing the new science that’s possible now with the upgraded light source,” she said. ​“If we can detect smaller metal impurities and other subtle defects that affect device performance, we can make more powerful technology.”

She anticipates continuing toward multimodal analysis — combining multiple measurement modalities within the same beamline to gain richer insights.

When asked what she would tell young scientists, she said, ​“Read the new scientific literature. See what resonates with you. Then, follow your curiosity.”