Quantum dots (QD), nano-sized crystals made from semiconductor materials, were first discussed in academic circles in the early 1980s. But it was Professor Moungi Bawendi (MIT), along with his colleagues professors David Norris and Christopher Murray, who brought to light the viability of the novel material.

Together, the team was able to successfully synthesize quantum dots, thus garnering great attention from the upper echelons of academia. So much so that the team’s paper has since acquired an astonishing 8,000 citations. Professor Taeghwan Hyeon (Seoul National University) even went on to call this “the legendary paper” as he welcomed Dr. Bawendi onto stage at the conference.

Dr. Moungi Bawendi shares recent developments in his lab at a plenary session at QD2016

“Quantum dots are a new material whose properties are different from the molecular materials that people are used to—ones that are unique enough that they’re worth trying in a variety of applications,” Bawendi told Samsung Newsroom in an interview following the conference. “A lot of what research is about is recognizing the unexpected and following that. This leads you to ask more questions.”

Those questions have since been explored by scholars all the world over. The expansion of quantum dot research has catalyzed a number of new methods to reliably synthesize variable sizes and types of nanocrystals, and has led to the discovery of numerous scientific and commercial applications, some of which have recently been realized.

Discovering New Properties

Speakers at the conference—an event that Bawendi likened to a “family reunion” of the QD community—showcased their own research and attempts at applying quantum dots in a variety of different industries.

Dr. Efros (US Naval Research Laboratory) talks to Samsung Newsroom at QD2016

One speaker, Dr. Alexander L. Efros of the US Naval Research Laboratory, explained that by using artificial particles such as quantum dots, people can, in theory, create materials that do not occur naturally. Improved tunable LEDs, lasers and displays are just a few notable examples of the progress scientists have already made on this front, he noted.

“Quantum dot technology advances mean that people can now dream of new solid state materials with properties that nature does not provide us with,” Efros stated.

One Material, Endless Possibilities

Bio-imaging is a major area teams are researching around the world; by leveraging various wavelengths, they hope to better visualize tissue for diagnostic and possibly even treatment purposes. For example, a POSTECH team shared their research on exploring the use of quantum dots of different sizes, which emit different colors, to detect cancer in mice. Recently, researchers have even begun to explore near-infrared (NIR) wavelengths, opening possibilities for even more enhanced resolution in such applications.

Another noteworthy application is photovoltaics, a method of converting solar energy into direct current electricity. Bawendi noted that this area specifically has recently seen tremendous progress in the application of quantum dots, with efficiency levels increasing from 3 percent to 10 percent in just five years. With further research, windows that help harvest solar energy using quantum dot technology could emerge. These windows could potentially play an important role in densely populated urban areas where rooftop surfaces are often too small for collecting all the energy required for building operations.

The display industry, specifically, is an area that has already experienced great advancements as a result of the utilization of quantum dot technology. Professor Kookheon Char of Seoul National University explained how the application of a thin layer of quantum dots can produce a light that very closely imitates natural light. The technology, he said, could ultimately lead to bendable light-emitting structures. Next-generation devices equipped with such structures could potentially be thinner, less expensive and allow for more precise color reproduction.

Other potential applications include sensors for self-driving cars and commercial cameras, better methods for nondestructive testing in the aviation and defense industries, and security ink with a unique optical signature to prevent counterfeit passports and currency.

Overcoming Limitations

Yet, as compelling as the possible applications of the novel material are, the speakers were quick to mention some of the challenges quantum dot researchers currently face. Quantum dots’ self-absorption properties, for example, limit some applications, while efficiency, toxicity, and in some cases stability are other areas that need improvement.

Samsung, however, is working to overcome these challenges, and has already shown great progress in doing so. The company’s 2015 SUHD TVs, for instance, were the first in the industry to be mass-produced with cadmium-free quantum dots.

Dr. Taeghwan Hyeon, a professor at Seoul National University and researcher at the Institute for Basic Science, told Samsung Newsroom about his response when he first heard about Samsung’s accomplishments.

Professor Taeghwan Hyeon (Seoul National University) at the QD2016 conference

“When the line-up was launched, many university labs around the world were having a hard time making cadmium-free quantum dots,” Hyeon noted. “I couldn’t believe it when Samsung announced that it had succeeded in not only developing, but mass-producing SUHD TVs with cadmium-free quantum dots.”

Approximately 90 percent of previous quantum dot studies involved particles with cadmium, explained Hyeon, which would have made it immensely difficult to create efficient light for a TV display. But this milestone is only the beginning for Samsung.

According to experts like those in attendance at QD2016, only time will tell what the future holds for quantum dots. The one thing they are certain about, though, is that the future will be an exciting one.

* Last week in Jeju City, Korea, top scholars from around the world came together to share the latest on quantum dot research at the 9th International Conference on Quantum Dots. Samsung, being the first in the world to commercialize cadmium-free quantum dot technology with its SUHD TVs, also took part, sharing its experiences in quantum dot research. This article is the third of a three-part series that highlights recent advancements in quantum dot technology.

** This article contains forward-looking statements regarding the research of quantum dot technology. These statements are based on assumptions and the current state of developments, and are thus subject to uncertainties.

In the past, materials were researched, developed and perfected long before they were applied to devices. Take liquid crystals, for example. They were first discovered in the late 1800s, and for decades were studied and defined in the academic realm. It wasn’t until the 1960s—almost a century later—that they were utilized in commercial products. Similarly, it took 30 years after its invention for lithium metal oxide to even be tested in batteries, and another decade before it made its official commercial market introduction.

Once materials such as these were introduced, however, they allowed for a steady and fairly rapid increase in device performance. In the display industry specifically, there has been enormous growth in the market because of such advancements up until now.

However, as the market becomes increasingly saturated, electronic materials innovations are beginning to fall behind the device revolution. This is mostly due to the fact that the device product life cycle is becoming much faster than that of the material. Now, the device itself is facing the limitations of this revolution in terms of product performance and functionality without the aid of novel materials.

To ensure consistent advancements and optimum functionality, both materials and devices have to be synchronized throughout the development process from the earliest stages of research so that performance requirements can be properly understood.

This was the message of the plenary session led by Dr. Hyuk Chang, Executive Vice President , Samsung Advanced Institute of Technology (SAIT), at the 9th International Conference on Quantum Dots held earlier this month.

Chang noted that the synchronization of materials research and device development can accelerate the enhancement of both the devices and the materials that they are made of, thus revitalizing the market.

“After all, innovation comes in many forms, and source technology is a foundational one,” Chang said.

The speeds of material and device innovation have changed over time. SAIT now aims to synchronize the two.

At Samsung, there are numerous organizations that carry out research and development. These include SAIT, where the company pioneers long-term, radical researches with five to ten year or more horizons; the R&D centers that explore next-generation products and platform technologies one to three years in advance; and business unit development teams that focus on commercialization, applying these latest technologies in product development.

Samsung is increasingly synchronizing its R&D efforts to bring core technologies like new materials to products more quickly.

One example is quantum dot technology. Confident that this specific technology could ultimately drive the future of display, among other areas, Samsung has researched the material and its advantages in earnest. In fact, researchers at SAIT started focusing on quantum dot technology over a decade ago, and have since registered numerous patents on the subject.

Through constant testing, evaluating and verifying the material from the earliest stages of device design, Samsung was able to incorporate quantum dots to create a revolutionary line-up of products—its 2015 SUHD TVs.

Example of a synchronized research roadmap

In doing so, the technology allowed for highly accurate color expression and better, brighter picture quality while improving overall energy efficiency at a lower cost—all with cadmium-free quantum dots. Considering that this was the first commercial application of the material, it created quite a buzz among academics in the field who had been eagerly anticipating such a milestone.

Despite these accomplishments, Samsung wanted to improve upon this technology and did so with its 2016 SUHD TVs, making them even more energy-efficient, and allowing them to display the picture quality more accurately.

“As a materials scientist, my previous work was in small-scale labs,” Chang explained. “It was overwhelming to see this technology make its way to mass production and even hit center stage at the industry’s top events like CES in just a decade. That’s the speed and scale of Samsung.”

As Samsung continues to research and refine the technology, the company predicts that quantum dots will further enhance display devices.

Chang noted that quantum dots could be applied in other ways, too, such as to improve the accuracy of image sensors, which could significantly advance autonomous cars. Experts note that the technology also has great potential in the areas of chemo- and bio-sensing. In fact, researchers at SAIT have already begun to utilize quantum dot technology in these areas, and are eager to continue to progress these developments.

“Just as Samsung’s SUHD TVs were realized by evolutionary quantum dot materials and boundless research for discovering novel physical phenomena, functional materials, value-added materials and next-generation devices must be closely interconnected,” Chang stated.

This, he believes, will accelerate materials innovations, leading to new functionalities in devices and the creation of novel devices. The synchronization of materials research and device development will also help to breathe new life into the massive global materials marketplace. By consistently providing added value with new materials, Samsung hopes to continue to revitalize the electronic devices industry.

* Last week in Jeju City, Korea, top scholars from around the world came together to share the latest on quantum dot research at the 9^th International Conference on Quantum Dots. Samsung, being the first in the world to commercialize cadmium-free quantum dot technology with its SUHD TVs, also took part, sharing its experiences in quantum dot research. This article is the second of a three-part series that highlights recent advancements in quantum dot technology.

** No official decisions have been made regarding the future application of the technologies and projects mentioned in this article.