How much do you know about the magical world of quantum dots?

From the general-purpose quantum computer being studied by Google to quantum communication, to quantum dot display technology, quantum research has attracted more and more public attention. However, due to the professionalism of this field, it is difficult for the public to understand deeply. Take the quantum dot technology that is the closest to everyone‘s life, for example, many people have bought quantum dot TVs without knowing what quantum dots are.

Finally, Peng Xiaogang, professor of Zhejiang University and senior expert on quantum dots, came out to popularize science for everyone! What exactly are quantum dots? What is the use of quantum dots? What are the advantages of quantum dots? How is China‘s research in the field of quantum dots? ...In this article, you can find the answer!

On July 22, TCL held the "Scientists face to face-Quantum Dot Display Science and Technology Forum" event in Zhejiang. Peng Xiaogang and more than 100 media reporters from all over the country discussed the current status and future prospects of quantum dot display technology face to face, using authoritative voices to reveal Open the mystery of quantum dots. Surprisingly, senior expert Professor Peng Xiaogang did not use too many obscure language to explain quantum dot display technology, so that everyone present understands this technology that affects the future of mankind.

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What are "quantum dots"?

At present, as all mankind is facing a shortage of natural resources, the inevitable energy crisis is also calling for the birth of new materials. And new materials of true scientific significance need to meet three conditions: reconstruct matter at the atomic and molecular level, achieve new or better performance, and change human life style. Quantum dots fully satisfy these three conditions, and at the same time they are the best luminescent materials ever discovered by mankind.

Simply put, quantum dots are extremely tiny inorganic nanocrystals invisible to the naked eye. Whenever stimulated by light or electricity, quantum dots will emit colored light. The color of the light we see is determined by the material and size of the quantum dots. Generally speaking, the luminescence can be changed by changing the size of the quantum dot crystal. colour.

For example, generally the smaller the quantum dot particles are, they will absorb long waves, and the larger the particles are, they will absorb short waves. For example, quantum dots with a size of 2 nanometers can absorb long-wave red and show blue. Quantum dots with a size of 8 nanometers can absorb short-wave blue and present red.

Since TCL launched Quantum Dot TV in 2014, it has officially started the marketization of quantum dots in China. Especially after the QUHD quantum dot TV was launched this year, major breakthroughs have been made in terms of audio and image quality, and the first to promote the civilization, commercialization and marketization of quantum dots.

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What is the use of "quantum dots"?

We all know that the imaging principle of an LCD panel can be summarized as adding liquid crystal molecules between two glass substrates. After voltage is applied, the molecular arrangement changes tortuously. The screen is formed by the collision of the electron group to produce the picture and the perspective reflection of external light. Picture. The liquid crystal itself does not emit light, and a high-quality CCFL cold cathode backlight is required to form a bright image. Subsequently, the backlight source was changed from CCFL to LED backlight source, which became what we often call LED TV.

TVs using quantum dot materials use blue LEDs as the backlight, and the optical materials using quantum dots are placed between the backlight and the LCD panel, so that bright colors can be obtained through red, green, and blue light with sharp peaks. If you don’t understand, let me put it another way. Quantum dots will form a thin film on the LED backlight of LCD TVs. When illuminated by blue LEDs, they can emit full-spectrum light to fine-tune the light. Significantly improve the color gamut performance and make the colors more vivid.

For example, it may not be appropriate. A traditional LCD TV is like a girl with only nude makeup when going out. Although it is beautiful enough, the face always looks less three-dimensional, while the quantum dot TV is like a girl with a full set of makeup. Pleasing to the eye, bright and moving.

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What are the advantages of "quantum dots"?

First of all, quantum dots are inorganic materials with strong stability, long life and not easy to aging. For example, most of the materials that make up rocks are inorganic materials, and most of the human body is made up of organic materials. Stones will not be affected by the sun every day. If we stand under the sun every day, I’m afraid it’s easy to get them. skin cancer.

Second, quantum dots have the advantage of full color gamut display and precise color control. The color gamut of traditional LCD panels is limited by the performance of the filter, but the emission spectrum of quantum dots is extremely narrow, so the color gamut is higher and can produce richer colors. The wide color gamut has a significant effect on the three-dimensional feeling and texture of the picture, just like a girl‘s face must be more three-dimensional and more beautiful after being shaded with a contour powder.

Third, quantum dots have the characteristics of low power consumption. Because each pixel of the quantum dot screen is also driven by an independent LED light source, the power consumption is also lower.

According to the first public test results of the domestic authoritative Territ Laboratory (National Radio and Television Product Supervision and Inspection Center), the core indicators of TCL QUHD TV far exceed the entire industry, especially the color gamut coverage is the highest value in the large database, and the peak brightness exceeds The industry average is 77.9%, and the color brightness exceeds the industry average by 26%.

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Are "quantum dots" materials toxic?

Someone once said that quantum dot TVs contain the element "cadmium" which is harmful to humans. But the fact is that normal use will not release the element, nor will it cause harm to the human body. Take a 55-inch quantum dot TV as an example, its cadmium content is equivalent to all the cadmium content in 1kg of rice that meets the World Health Organization. So, will we be poisoned after eating one kilogram of rice? The answer is no. Moreover, the new materials in quantum dot TVs will be strictly encapsulated and will not leak or cause harm to the human body.

TCL quantum dot TV has passed the European Union‘s environmental certification, so TCL quantum dot TV is a product that meets safety and environmental protection standards, and consumers can buy and use it with confidence. Those who accuse quantum dot TVs of containing cadmium and endanger people‘s health are purely for the purpose of commercial operation, advocating the harm of quantum dot TVs.

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What is the significance of developing quantum dot displays?

Peng Xiaogang introduced that the core technology of the display industry, from CRT, to LCD, to OLED, has always been in the hands of foreign giants, and OLED TVs are more completely dominated by South Korean companies LG. At present, my country‘s imported backlight modules have very large foreign exchange consumption. If all the forces in China unite to complete the quantum dot technology, this situation will be broken. Quantum dots are of great significance to the transformation of the national economy.

Quantum dot display technology is mainly divided into two stages: photoluminescence and electroluminescence. At present, TCL, Hisense, South Korea‘s Samsung and other companies have achieved the landing of photoluminescence products. It is understood that based on the first stage of photoluminescence, its performance is superior to that of existing TVs, and breakthroughs have been achieved in terms of color, power consumption and overall effects. As for the second stage of electroluminescence, Peng Xiaogang bluntly stated that it will be the most likely next-generation display technology option for mankind.

The electroluminescent quantum dot (QLED) technology is very valuable, and it will have earth-shaking changes to the entire industry. QLED will be able to self-illuminate like OLED, without backlight, and realize flexible display, ultra-thin shape, but without the defects of OLED, it is a disruptive technological innovation. For QLED, China leads the world in technology and is the leader of the world‘s first echelon.

In the future, when electroluminescence quantum dot technology is put into application, the lighting and display industries will be disrupted. By then, the use of quantum dots can be used to print TVs like newspapers, which can effectively reduce waste and will also play an important role in alleviating the global energy crisis. It can be said that the future of "quantum dots" is bright.

Thanks to the efforts of TCL and other companies, the quantum dot printing display is moving from a "laboratory" to a landing application. As the only domestic enterprise that has completed the vertical integration of the industrial chain, TCL has been prioritized and balanced in five major areas: quantum dot material synthesis, quantum dot printing devices, printing and display technology, G4.5 printing display platform, and G8.5 printing display platform. Develop and seize the cutting-edge technology in the field of printing and display.

Quantum dot display technology has received the focus of the national "Thirteenth Five-Year Plan". For example, the Ministry of Science and Technology recently announced a list of national key research and development plans. The "Research on Key Materials and Devices for Quantum Dot Luminescence Display" led by Peng Xiaogang was selected as a "strategy" The Ministry of Industry and Information Technology also announced that quantum dot printing and display is a key technology for national key development. With the joint efforts of the state, enterprises, and R&D institutions, China‘s quantum dot display technology is expected to take the lead in achieving new breakthroughs in the world, and the future development of quantum dots is unimaginable.

Isn‘t such a powerful technology the perfect material to improve the compelling quality? Next time, when you drink and brag with your buddies or chat with your sisters, let them use quantum dot display technology in popular science, which can also be considered as a contribution to China‘s popular science cause. By the way, if you happen to need a TV, don’t hesitate, it’s TCL QUHD Quantum Dot TV!
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