Television technology has leveled up over the past few years. First there were high-definition TVs and now there are TVs with OLED and QLED screens. QLED TVs, which , use particles called “quantum dots” to generate their pixels.

Quantum dots, which are 10,000 times smaller than the width of a human hair, are unique materials that generate very specific colors of light. Researchers, including , 天美影视传媒 professor of chemistry, hope that quantum dots can one day be useful for more than just illuminating screens.

Cossairt鈥檚 lab makes quantum dots for a variety of potential applications, including advanced computing. UW News asked her to compare the quantum dots in QLED TVs with the ones her lab makes.

So what exactly is a quantum dot?

Brandi Cossairt: It’s a material built from a lattice of atoms. Think about diamonds, which are made from a lattice of carbon atoms. If you take a diamond and you shrink it down to a very, very, very small scale to where there are only a few, maybe 100, carbon atoms 鈥� that’s kind of what a quantum dot looks like. Our quantum dots have the exact same structure as a diamond, except instead of carbon atoms, it contains other atoms, such as indium atoms and phosphorus atoms, or cadmium atoms and selenium atoms.

How do quantum dots generate light?

BC: Our quantum dots are semiconductors. This is a fundamental type of material that is defined as having an energy gap between where the electrons are and where they are not. This is different from a material like a metal, for example, where it’s easy for electrons to move around. In a semiconductor, the electrons and empty spots are very separated in terms of energy, and you need to apply energy to move electrons into empty spots. And once you’ve moved one, it’s “excited,” and it needs to “relax” back down to where it came from. One way that it does that is by releasing a photon, generating light.

Because quantum dots are so small, the color of light that they generate depends on their size. For example, larger quantum dots generate a red color and smaller quantum dots generate a blue color. This is different from a bulk semiconductor where the color of light is fixed, regardless of its size. So that’s kind of fun: By changing the size of the dot, you can change the color of light that is generated. That’s why we like them a lot.

What’s happening in a QLED TV?

BC: The way that current quantum dot TVs work is they shine a blue LED through a film containing a mixture of red- and green- emitting quantum dots. The quantum dots absorb that blue light, get excited, and then release red and green photons. Mixing that with blue from the LED is what generates the red, green and blue color pixels in the TV. You can precisely mix little bits of blue and green and red to get any color you want. That’s how you get all the colors the human eye can see.

What else do you want to use quantum dots for?

BC: The hope is that in the future we might be able to use light generated from quantum dots to do very large computations. Currently, we are limited in terms of the number of transistors we can pack onto a computer chip. Eventually, we’re going to reach some fundamental limit of how much information we can process with our chips.

People are trying to come up with new ways to get beyond the traditional way we do computing with zeros and ones. Photons are nice because they have quantum properties, such as the ability to exist in two different states at the same time, which allows us to use them to process much more information. We’re very far from that reality, but the idea is provocative and exciting. It’s an opportunity for scientists to think and dream and discover.

What’s getting in the way of making this a reality?

BC: In order to do something productive, you need to have many identical photons interacting, and that’s the hard part. You need all the photons that are generated to be exactly the same: exactly the same color and frequency and phase and all that stuff. And that’s really hard.

Right now, if we made 1,000 single quantum dots, they wouldn’t all give you exactly the same flavor of photon. They’d be close enough for a TV 鈥� that collection of quantum dots would give you a really nice red for example. But it’d still be a span of energies. It’s good enough for our eyeballs, but it’s not good enough for a quantum information system.

What are other challenges that you’re working on?

BC: So even if we did make quantum dots better at emitting pure, indistinguishable, single photons, we still need a way to put them onto a chip to do these computations. We need to position them exactly where we want them. It’s very hard to do. Recently we worked with our collaborator, , UW associate professor of both mechanical engineering and materials science and engineering, to .

Here’s what we did: We took our quantum dot, which is really tiny 鈥� and it needs to be tiny to do all the fun, cool light emission stuff 鈥� and then we buried it into a big shell of some other material. Now we have something that’s 100 nanometers in diameter, instead of 3 nanometers in diameter. A 100-nanometer object is a bit easier to manipulate one particle at a time.

Then we made an ink containing these 100 nanometer particles, which we ejected through the nozzle of an inkjet printer using an electric field. This allowed us to strategically position these particles on photonic cavities, which is kind of like the building block for a photonic quantum computer. So that’s exciting.

This has been a really fun, collaborative project that also included a variety of researchers, such as Devin and , UW professor of both physics and electrical and computer engineering. My group was responsible for the synthesis of the quantum dots and putting them into their shells. This project has really gone far, and we’re excited to see what we can do with it next.

For more information, contact Cossairt, who is the Lloyd E. and Florence M. West Endowed Professor of Chemistry and a researcher with the UW Clean Energy Institute, at cossairt@uw.edu.

Two 天美影视传媒 researchers have been named AAAS Fellows, according to an by the American Association for the Advancement of Science. They are among 502 newly elected fellows from around the world, who are recognized for their 鈥渟cientifically and socially distinguished achievements鈥� in science and engineering.

A tradition dating back to 1874, election as an AAAS Fellow is a lifetime honor, and all fellows are expected to meet the commonly held standards of professional ethics and scientific integrity.

This year鈥檚 UW AAAS fellows are:

, the Lloyd E. and Florence M. West Endowed Professor of Chemistry and a researcher with the UW Clean Energy Institute, is honored for her contributions to the development of nanoscale materials, which are in the size range of approximately 1 to 100 nanometers, for applications in energy and advanced electronics. For reference, 1 nanometer is about 100,000 times smaller than the width of a human hair. Cossairt investigates how crystalline nanoscale materials come together, grow and shrink and react with other compounds and photons. Her research includes synthesizing materials with novel physical and surface chemistry properties, such as inorganic quantum dots with use in lighting, displays, catalysis and quantum information technology. A UW faculty member since 2012, Cossairt has earned numerous honors, including a Sloan Research Fellowship, a Packard Fellowship, an NSF CAREER Award and a teacher scholar award from the Camille and Henry Dreyfus Foundation. She also co-founded the Chemistry Women Mentorship Network to provide support, encouragement and career-development opportunities for women in the chemistry field.

, professor of pharmacy and of global health, was recognized for his work to better monitor the safety of essential medicines and vaccines, especially in low- and middle-income countries. He directed a study assessing the safety of antimalarial drugs among pregnant people in sub-Saharan African nations and has been involved in several other initiatives to assess the safety of vaccines used during pregnancy. He researches the global burden of antimicrobial resistance and has strengthened pharmacy services in numerous countries. Dr. Stergachis is an elected member of the National Academies of Medicine, fellow of the American Pharmacists Association and fellow of the International Society for Pharmacoepidemiology. He holds adjunct faculty appointments in the Departments of Health Metrics & Evaluation and in Epidemiology.

Twenty scientists and engineers at the 天美影视传媒 are among the 38 new members elected to the Washington State Academy of Sciences for 2021, according to a July 15 . New members were chosen for 鈥渢heir outstanding record of scientific and technical achievement, and their willingness to work on behalf of the Academy to bring the best available science to bear on issues within the state of Washington.鈥�

Current academy members selected 29 of the new members. An additional nine were elected by virtue of joining one of the National Academies.

New UW members who were elected by current academy members are:

• , professor and Port of Tacoma Chair in Environmental Science at UW Tacoma, director of the and science director of the , 鈥渇or foundational work on the environmental fate, behavior and toxicity of PCBs.鈥�
• , professor of psychology, 鈥渇or contributions in research on racial and gender inequality that has influenced practices in education, government, and business鈥� and 鈥渇or shifting the explanation for inequality away from individual deficiencies and examining how societal stereotypes and structures cause inequalities.鈥�
• , professor of chemistry and member faculty at the , 鈥渇or leadership in the innovative synthesis and chemical modification of nanoscale materials for application in light emission and catalysis.鈥�
• , professor of global health and of environmental and occupational health sciences, and founding director of the , 鈥渇or work on the health impacts of climate change, on climate impact forecasting, on adaptation to climate change and on climate policy to protect health.鈥�
• , professor of environmental and forest sciences and dean emeritus of the College of the Environment, 鈥渇or foundational studies of regional paleoenvironmental history and sustained excellence in academic leadership to catalyze and sustain transformative research and educational initiatives.鈥� Graumlich is also president-elect of the American Geophysical Union.
• Dr. , the Joseph W. Eschbach Endowed Chair in Kidney Research and co-director of the , 鈥渇or pioneering contributions and outstanding achievements in the development of the novel wearable artificial kidney, as well as numerous investigator-initiated clinical trials and multi-center collaborative studies.鈥�
• , professor of environmental chemistry and chair of the Physical Sciences Division at UW Bothell, 鈥渇or leadership in monitoring and understanding the global transport of atmospheric pollutants from energy production, wildfire, and other sources, as well as science communication and service that has informed citizens and enhanced public policy.鈥�
• , professor and chair of psychology, 鈥渇or contributions demonstrating how psychological science can inform long-standing issues about racial and gender discrimination鈥� and 鈥渇or research that has deep and penetrating implications for the law and societal efforts to remedy social inequities with evidence-based programs and actions.鈥�
• , the Leon C. Johnson Professor of Chemistry, member faculty at the and chair of the Department of Chemistry, 鈥渇or developing new spectroscopy tools for measuring energy flow in molecules and materials with high spatial and temporal resolution.鈥�
• , professor of astronomy, 鈥渇or founding the and leading the decades-long development of the interdisciplinary modeling framework and community needed to establish the science of exoplanet astrobiology鈥� and 鈥渇or training the next generation of interdisciplinary scientists who will search for life beyond Earth.鈥�
• , professor and chair of aeronautics and astronautics, 鈥渇or leadership and significant advances in nonlinear methods for integrated sensing and control in engineered, bioinspired and biological flight systems鈥� and 鈥渇or leadership in cross-disciplinary aerospace workforce development.鈥�
• , associate professor of chemistry and member faculty with the Molecular Engineering and Sciences Institute, 鈥渇or exceptional contributions to the development of synthetic polymers and nanomaterials for self-assembly and advanced manufacturing with application in sustainability, medicine and microelectronics.鈥�
• Dr. , Associate Dean of Medical Technology Innovation in the College of Engineering and the School of Medicine, the Graham and Brenda Siddall Endowed Chair in Cornea Research, and medical director of the UW Eye Institute, 鈥渇or developing and providing first class clinical treatment of severe corneal blindness to hundreds of people, for establishing the world premier artificial cornea program in Washington, and for leading collaborative research to translate innovative engineering technologies into creative clinical solution.鈥�
• Dr. , professor of medicine and director of the , 鈥渇or global recognition as an authority on drug and vaccine development for viral and parasitic diseases through work as an infectious disease physician and immunologist.鈥�
• Dr. , professor of pediatrics and of anesthesiology and pain medicine, and director of the , 鈥渇or outstanding leadership in pediatric anesthesiology and in the care of children with traumatic brain injury鈥� and 鈥渇or internationally recognized expertise in traumatic brain injury and direction of the Harborview Injury Prevention and Research Center for the last decade as an exceptional mentor and visionary leader.鈥�

UW members who will join the Washington State Academy of Sciences by virtue of their election to one of the National Academies are:

• , professor of biostatistics, 鈥渇or the development of novel statistical models for longitudinal data to better diagnose disease, track its trajectory, and predict its outcomes鈥� and 鈥渇or revolutionizing how dynamic predictors are judged by their discrimination and calibration and has significantly advanced methods for randomized controlled trials.鈥� Heagerty was elected to the National Academy of Medicine in 2021.
• , the Bill and Melinda Gates Chair in Computer Science and Engineering, 鈥渇or foundational contributions to the mathematics of computer systems and of the internet, as well as to the design and probabilistic analysis of algorithms, especially on-line algorithms, and algorithmic mechanism design and game theory.鈥� Karlin was elected to the National Academy of Sciences in 2021.
• , professor emeritus of applied mathematics and data science fellow at the , 鈥渇or inventing key algorithms for hyperbolic conservation laws and transforming them into powerful numerical technologies鈥� and 鈥渇or creating the Clawpack package, which underpins a wide range of application codes in everyday use, such as for hazard assessment due to tsunamis and other geophysical phenomena.鈥� LeVeque was elected to the National Academy of Sciences in 2021.
• , the Benjamin D. Hall Endowed Chair in Basic Life Sciences and an investigator with the Howard Hughes Medical Institute, 鈥渇or advancing our physical understanding of cell motility and growth in animals and bacteria鈥� and 鈥渇or discovering how the pathogen Listeria uses actin polymerization to move inside human cells, how crawling animal cells coordinate actomyosin dynamics and the mechanical basis of size control and daughter cell separation in bacteria.鈥� Theriot was elected to the National Academy of Sciences in 2021.
• , professor and chair of biological structure, 鈥渇or elucidating cellular transformations through which neurons pattern their dendrites, and the interplay of activity-dependent and -independent mechanisms leading to assembly of stereotyped circuits鈥� and 鈥渇or revelations regarding the fundamental principles of neuronal development through the application of an elegant combination of in vivo imaging, physiology, ultrastructure and genetics to the vertebrate retina.鈥� Wong was elected to the National Academy of Sciences in 2021.

New members to the Washington State Academy of Sciences are scheduled to be inducted at a meeting in September.

“It is really an honor 鈥� humbling and amazing,” said Cossairt, an assistant professor in the UW Department of Chemistry. The fellowship includes a five-year research grant of $875,000.

Cossairt and the members of 鈥� at last count nine graduate students, one postdoctoral fellow and several undergraduates 鈥� pursue research to synthesize and manufacture new molecules for applications in green technology such as solar energy and fuel production.

“I like to group chemists into two categories 鈥� makers and measurers,” said Cossairt. “We’re definitely makers.”

Cossairt works on crystal formation at the “nanoscale,” a window of size between 1 and 100 nanometers. For reference, 1 nanometer is 100,000 times smaller than the width of a human hair. This range of exploration is intermediate between the scale of individual molecules or atoms and larger 鈥� but still microscopic 鈥� realm of bacteria or crystalline aggregates. It is also a scale with unique properties, especially for the Cossairt studies.

“The properties of materials at this scale just tend to be really different than if they were smaller or larger,” said Cossairt. “In the nanoscale, when you change the size of these nanocrystals, their electronic structure changes. You can alter what color of light they absorb and what color they emit, for example.”

Many of Cossairt’s research projects explore the light-interacting properties of nanocrystals. One goal is to synthesize new light-emitters for energy-efficient lighting and electronic displays. Other projects aim to produce new, efficient light-absorbing compounds for solar cells.

Cossairt’s research also explores new methods for fuel production. Just as she hopes semiconductor nanocrystals could harvest light for solar energy, she is looking at how nanocrystals could harvest light directly for fuel formation, such as splitting water molecules to produce hydrogen. In a separate project, Cossairt and her team are exploring how nanocrystals could absorb a pollutant, such as carbon dioxide gas from industrial output, and convert it into octane, a useful hydrocarbon fuel.

In addition to these green applications for nanocrystals, Cossairt and her laboratory study new ways to manufacture nanocrystals quickly and efficiently.

“The tools to work at this scale are developing, and if you don’t make your crystals the same size they won’t all have the same properties,” said Cossairt. “What we really try to do is to make these nanomaterials cheaply and uniformly.”

Part of Cossairt’s motivation in these projects is a sense of social responsibility for the challenges of the 21st century.

“As a scientist, I ultimately want to do things that help people,” she said. “We need green energy, and lots of it, and my background in materials science and chemistry makes this application the right space for my training.”

Cossairt earned a bachelor’s degree in chemistry from the California Institute of Technology and a doctorate from the Massachusetts Institute of Technology. She began to study nanocrystal properties as a postdoctoral researcher at Columbia University before joining the UW faculty in 2012. Cossairt is the third Packard Fellow to come from the UW Department of Chemistry and the for the university, seven of whom are still at the UW.

Every year, about 50 universities are invited to nominate two faculty members who are in the first three years of their careers for consideration as a fellow. A 12-member scientific panel recommends fellows each year for final selection by the Packard Foundation Board of Trustees, in fields from biology to engineering.

“The previous Packard Fellows have been astounding, so I feel like I’m in great company,” said Cossairt.

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For more information, contact Cossairt at 206-543-4643 or cossairt@uw.edu.