The December 2022 issue of IEEE Spectrum is here!

Close bar

Microwave Oven Is Key to Safer Quantum Dot Manufacturing

Scalable manufacturing process could lead to new generation of LED lighting

2 min read
Microwave Oven Is Key to Safer Quantum Dot Manufacturing
Photo-illustration: Yagi Studio/Getty Images

As we noted earlier this month, quantum dots have finally made a broad commercial impact on LED technology. So now it’s time to refine the processes for making them and to increase profit margins.

Now researchers at Oregon State University (OSU) have thrown their hat into the ring, presenting a manufacturing method for quantum dots that promises a new era in LED lighting.

In research published in the Journal of Nanoparticle Research, the OSU researchers employed a so-called “continuous flow” chemical reactor. Chemicals were continuously put into the reactor and came out as a continuous stream of product. This continuous flow setup makes the process cheaper, faster, and highly scalable. Meanwhile, using microwaves to heat the reagents—with a machine that operates on more or less the same principle as your microwave oven at home—addresses the issue of how to maintain precise temperature control during the chemical process.

The researchers claim that this method leads to precisely sized and shaped quantum dots that are consistent in their composition. They believe that this development will mark a big change in LED lighting.

“We may finally be able to produce low-cost, energy-efficient LED lighting with the soft quality of white light that people really want,” said Greg Herman, an associate professor of chemical engineering at OSU, in a press release. “At the same time, this technology will use nontoxic materials and dramatically reduce the waste of the materials that are used, which translates to lower cost and environmental protection.”

The environmental benefit of the quantum dots stems from the use of copper indium diselenide, which is a more environmentally benign material than the cadmium that is typically used in LED lighting systems.

Because the process will give manufacturers the ability to fine-tune the size and shape of the quantum dots, that flexibility should make them able to produce dots for a variety of applications. Smaller dots emit green light, while the larger dots emit light in the orange to red range.

The OSU researchers believe that their precision manufacturing method will yield better color control than other quantum-dot-making techniques. So much so that they foresee quantum dots produced via this method providing a cheaper alternative in an array of applications including optics, electronics, and biomedicine.

The Conversation (0)

The Transistor at 75

The past, present, and future of the modern world’s most important invention

2 min read
A photo of a birthday cake with 75 written on it.
Lisa Sheehan
LightGreen

Seventy-five years is a long time. It’s so long that most of us don’t remember a time before the transistor, and long enough for many engineers to have devoted entire careers to its use and development. In honor of this most important of technological achievements, this issue’s package of articles explores the transistor’s historical journey and potential future.

Keep Reading ↓Show less