Ruiqi Zhang sliced a tiny quantum dot LED into nanoscale-thin slivers to see what happens inside when it lights up. What that MIT graduate student discovered could change the screens you look at every day.
Quantum dots are super-small semiconductor particles that glow in extremely pure, vivid colors. You've likely seen them already — they're used in some of today's best computer and TV displays. Unlike regular LEDs that use thousands of tiny lightbulbs, or OLEDs that use glowing organic molecules, quantum dot screens produce richer, more energy-efficient light by precisely controlling what color each particle emits.
The problem? Blue quantum dot LEDs wear out 50 to 100 times faster than their red and green counterparts, making them impractical for commercial products like phones and TVs.
"If you use them in an LED display, your TV might last for just a few months before it stops working," Zhang says. "We wanted to understand what is different about the blue quantum dot LEDs."
Working with mentors including Moungi Bawendi — who won the 2023 Nobel Prize in Chemistry for discovering quantum dots — and Vladimir Bulović, an MIT professor who has worked on LED displays since 2000, Zhang and his team found a surprisingly simple fix. Coating the LEDs with a clear acrylate-based resin, the kind similar to what's used in adhesives and coatings, extended their lifespan by up to 5,000 times.
The improvement comes from protecting the quantum dots from the physical degradation that happens during operation. The team examined cross-sections of the tiny devices under powerful microscopes to understand exactly why the coating works so well.
"The insights into how and why quantum dot LEDs get modified during their operation open the possibility of fixing everything that holds back commercialization of QD-LED displays," Bulović says. "This technology can provide a light source like never before — pure in color, paper-thin and of large area, transforming how we produce both displays and general lighting."
The research, published in Science Advances, could eventually lead to brighter, more colorful screens in everything from flat-screen TVs and smartphone displays to augmented reality headsets, medical imaging devices, and large ambient lighting panels. The process is simple and scalable, meaning manufacturers could potentially adopt it without major changes to how they currently make displays.