At the intersection of physics, electrical engineering and materials science sits new University professor Hyunseok Kim. Since joining the faculty in January, Kim has led cutting-edge research in LED nanotechnology.

Kim is in his second semester at the University and teaches ECE 444: IC Device Theory & Fabrication. 

“The class is about teaching students how to fabricate semiconductor chips,” Kim said. “Throughout the experience, students get a holistic knowledge about both theory and hands-on skills.”

When he’s not lecturing, Kim spends his time in the lab working on microLED technology. His research is funded by a grant from the SAMSUNG Global Research Outreach Program.

LED falls under the broader line of optoelectronics, a discipline that deals with light-emitting or light-detecting devices.

“Optoelectronics is a field where electronics and optics are combined,” Kim said. “TVs (and phones) are a good example because you apply some electric current, and the light turns on.”

Currently, visual technology employs organic LED or liquid-crystal displays in its products. OLEDs use organic materials to emit light but degrade easily over a short lifespan; LCDs employ backlights rather than individual pixels, giving them better lifespans than OLEDs. However, the inability to fully turn the backlight off limits the efficacy of LCDs.

Kim is working to take the most useful parts of both technologies and create a new, more effective product.

“You can combine the advantages of both if you use inorganic material as a self-emitting material, which is called microLED display,” Kim said.

As an engineer and applied scientist, Kim focuses on the direction the market is trying to move. With the recent rise in popularity of virtual reality, he believes microLED technology is a good candidate for future related technologies.

“Displays are getting closer and closer to human eyes,” Kim said. “You can imagine that if they’re getting closer, you don’t want some kind of screen door effect, meaning that you can individually see the pixels.”

Creating displays to accommodate these changes calls for much higher pixel density. Without more advanced displays, the user can see individual pixels, ruining the intended immersive experience.

MicroLED is a new technology and has yet to offer solutions to rising industrial needs. Kim’s research competes with the industry in its efforts to make breakthroughs by providing a completely out-of-the-box perspective.

“So my idea, for example, was that instead of moving (pixels) one by one (and placing them side by side on display panels), we just move them as a large plane, stack them up (and then fabricate the pixels),” Kim said. “Through that approach, you can get much higher density.”

Kim’s other approach involves a “self-alignment process,” where he creates millions of stacked RGB pixels and then disperses them for assembly.

“This is how we are not manually placing (the pixels) one by one,” Kim said. “We just pour them, and then they self-assemble into the interposer.”

The ultimate goal is to integrate pixels onto display panels by increasing the number of pixels per inch without adding to the time and labor needed.

“What I’m interested in is this new methodology that can enable a new fabrication technology, which in turn enables a new form factor in semiconductor devices (and platforms),” Kim said.

Looking forward, Kim hopes to contribute to advancements in microLED technology long into the future.

“Specifically for this microLED, I think the timeline for maturing this technique will be two or three years,” Kim said. “But I am thinking of a lot of possibilities for using this new technique — self-assembly — for other device platforms. That will continue for hopefully a decade.”

Kim has not only made progress in his field but learned valuable lessons about mentorship and working with a team of researchers.

“As an experimentalist, I learned that teamwork is really important, especially when I’m learning to work with my group (and) my students as well,” Kim said. “Trusting each other, being on the same page and creating a good group culture is really important.”

A diverse teaching and research career is on the horizon for Kim as he settles in, and his time at the University has only just begun.

“I hope I can grow up and learn new things about how to manage large groups and how to inspire students in a positive way,” Kim said. “From this, I hope to grow my group and expand my collaboration with other excellent faculty members.”

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