Start with a college teacher

Chapter 647 Decryption (1)

"That's right, the secret lies in those little light bulbs!"

Shen Guanglin readily admitted.

"What is behind this is indeed not a whole piece of glass screen, nor is it a movie projection screen. It is indeed a screen composed of small light spots. Each light spot is actually a light bulb, which can also represent a pixel. It is similar to our TV. The distribution of pixels in the machine has the same meaning, and the analysis method is the same.”

After speaking, Shen Guanglin also directed the staff to type a poem on it.

Seen sideways as a peak on the side of the ridge, the height varies from far to far.

This is Lushan Mountain written by Su Shi, which is similar to what Li Bai wrote.

Shen Guanglin asked them to write Li Bai's as well:
The incense burner in Rizhao produces purple smoke, and you can see the waterfall Hanging Qianchuan in the distance.

Moreover, these words can also fall from the top, just like falling from a waterfall.

It's fun, isn't it? There's more fun out there.

Someone Shen directly took out two game controllers, and played a cube game with the bearded man on the spot.

That's right, this is already the cube game he invented - sinking cubes, not Tetris anymore.

At present, this game is very famous, and many people are saying that it is a way for Professor Shen to relieve his mind and relax after his scientific research work.

In short, celebrities are famous for everything they do.

After playing a game, the bearded man in the Middle East plucked out a few of his beards in astonishment, indicating that he has gained a lot of knowledge. Get me one of these fun things. Money is not a problem.

If money is no object, neither is the equipment.

If it doesn't work, this device can be disassembled and given to him.

However, this matter can be discussed later. Shen Guanglin briefly talked about the working principle of this screen.

This thing looks very sci-fi, but the principle is not complicated, and many of them are not newly created technologies, but only a certain degree of integration of existing technologies.

Probably, there are only two difficulties here. One is the bulbs that can emit light of various colors, and the other is how to control these light spots and how to divide the display modules.

But these are not things that can be explained in one sentence, it is right to make everyone feel awesome.

Mr. Shen's purpose is to make an amazing thing very simple, and it is very simple for everyone to hear, but when he really wants to do it, he finds it is still difficult.

Afterwards, Shen Guanglin asked back: "Do you know what this little light bulb is?"

No one in the audience knew.

Some people want to guess but dare not guess, ordinary light bulbs can also change colors?

It is understandable that bulbs can emit light of different colors, just like fluorescent lamps, which can emit various colors of fluorescence according to different paints.

However, the color of the traditional light source is fixed, red light is red light, and green light is green light.

The same light bulb can also change color, but I have never seen it before.

Even, I have never heard of it before. Could it be that Sichuan Opera changed faces?

What is the principle?
This is another question that is difficult to explain clearly in one sentence, but Shen Guanglin has already had the entire research and development process filmed as a documentary, so let's watch it while playing it on the big screen.

One of the original intentions of this new product launch is to promote Shen's awesomeness.

The definition of the large screen is good, and the closer to the back row, the higher the definition.

That's right, as everyone guessed, this thing is actually a light-emitting diode!Also called LED.

In the scope that everyone already knows, there are many types of light-emitting diodes, and they can indeed emit light of different colors.

For example, gallium arsenide diodes can emit red light, and gallium phosphide diodes can emit green light. However, what everyone does not know is that there are really blue light-emitting diodes, that is, gallium nitride diodes.

For a long time in the past, many people have been thinking about inventing blue light-emitting diodes, but they have never been realized.

Today, the LED working group in Shen Guanglin's laboratory has come true!

Red, green, and blue are the three primary colors of light, and all colors can be mixed, including black, white and gray.

In other words, as long as the blue light diode is invented, an LED light source that emits white light can be produced.

This is so important for lighting!

What are the benefits of using LED lights for lighting?Energy saving, environmental protection, long life, small size.

Many people began to ask, how was the blue LED invented?
So many people in the world are researching this, but there has been no breakthrough. Shen Guanglin's laboratory has not only made a breakthrough, but it is already ready for practical application.

Well, the invention of the blue LED is a good story that took a long time to craft.

The story unfolds slowly on the colorful screen.

In the documentary, Shen Guanglin's laboratory discovered that blue light diodes can be traced back to 4 years ago. At that time, he suddenly became interested in solar photovoltaic power generation.

At that time, Professor Shen was very interested in satellites and solar power generation, so he went to Jinmen to study for more than half a year.

However, after staying in Jinmen for so long, it is wrong to say that there is no gain, but it is not accurate to say that the gain is great.

Because, after the Academy of Sciences brought the technology of solar power generation to Jinmen, this technology has not improved for more than ten years.

There are several reasons, lack of money is the most important factor, and the application area is narrow, except for satellite use, other things will not be used.

However, it was at this time that Professor Shen learned that the current photovoltaic application products are all realized through the processing of semiconductors.

Photovoltaic panels such as monocrystalline silicon and polycrystalline silicon belong to the application of silicon-based semiconductors. Other semiconductors include germanium, gallium arsenide, copper indium gallium selenide, and so on.

It was in the process of developing solar cells that Professor Shen learned that gallium arsenide has the highest photoelectric conversion efficiency.

This is a good thing.

As a result, he became interested in the metal gallium.

Although gallium is very rare, it has many uses. Gallium can not only be used for phase control radar, but also for solar power generation, and it can also be used for research and development of light-emitting diodes.

It was in a series of experiments that they discovered that different compounds of gallium could make different diodes, which would emit different kinds of light.

Since gallium arsenide diodes can emit red light and gallium phosphide diodes can emit green light, there should also be a gallium compound that can emit blue light.

Based on this judgment, Professor Shen made a bold judgment based on Mendeleev's periodic table of chemical elements and the distribution of electrons outside the nucleus, combined with the wavelength of blue light: the substance that emits blue light diodes must exist !
Therefore, developing a new gallium compound that can emit blue light has become a research topic of a project team in his laboratory.

Since both arsenic and phosphorus in gallium arsenide and gallium phosphide are trivalent, arsenic trioxide is a poisonous arsenic, and PH3 is a highly toxic gas. Professor Shen thought for a long time, but did not think of a suitable compound of gallium.

The story does not end here, but just begins.

Professor Shen's laboratory has successfully developed transgenic insect-resistant cotton. During the planting and promotion of insect-resistant cotton, Professor Shen discovered that the main component of the fertilizer used is nitrogen fertilizer, and both urea and ammonia bicarbonate can emit a pungent smell. , this pungent smell is ammonia NH3.

So, he suddenly thought that the nitrogen in ammonia NH3 is trivalent, and another gas is nitrogen trifluoride NF3.

Can gallium nitride be made by chemical reaction?

Do it when you think of it.

Therefore, Professor Shen formulated a plan to synthesize gallium nitride. Through step-by-step experiments, gallium nitride was synthesized in this way!

Sure enough, gallium nitride emits blue light when it is powered on, and the blue light LED was born!
There was another warm applause from the audience.

The invention process of blue LED is really a good story, which includes Professor Shen's intelligence, Professor Shen's patriotism, Professor Shen's good thinking, and Professor Shen's persistence.

In the documentary, the process of inventing gallium nitride is so complicated and simple, which fully reflects the wisdom of Professor Shen and the execution ability of the laboratory staff.

It's really amazing.

You know, the actual situation is not like this.

Mr. Shen rushed to gallium nitride early in the morning after he thought of blue light LEDs. He actually knew that gallium nitride can emit blue light.

Moreover, his laboratory has been experimenting for a long time only to master the synthesis method of gallium nitride, and through a series of research, finally mastered the method of mass production.

It was on this basis that he decided to publish this result.

In fact, two years ago, the results of the discovery of blue LEDs could be released, but someone from Shen refused to allow it, and forcibly suppressed it.

In this new product launch event, Shen just talked about the research and development process lightly, as if it was not worth mentioning.

In fact, the people in the audience are already overwhelmed with admiration.

This is the case with the invention of the treatment of leukemia just now, and the same is the case with the invention of blue light LED.

The theoretical basis is given, and then the research and development is successful.

After the documentary was finished, Shen Guanglin had someone push two wooden houses over to prepare for a comparative experiment.

Only when there is contrast, can there be harm. Let you take a look at the effect of LED white light lighting.

After all, lighting is the most valuable of all LED applications.

Somebody Shen had someone prepare two lamps, one of which was a 100W incandescent lamp and the other was a 10W LED lamp.

This matter was done by classmate Jiajia, and classmate Xiao Zhu helped.

Men and women match, work is not tired.

After the arrangement was completed, before the electricity was sent, he asked everyone to guess, which light would be brighter?
You know, the power is also ten times worse.

In fact, seeing this scene, everyone has already guessed: Shen is so prepared, nine out of ten because the LED lights are brighter.

Of course, there is no need to think about the test results. The LED lights are the best. The incandescent lights emit yellow light and are rather dim. The LED lights are dazzling white light, which is particularly pure.

But everyone still can't believe it, is it so advantageous for LED lights to be used for lighting?

Then go ahead and compare, but comparing incandescent lamps can't show the brilliance of LEDs, and there are other things to do next.

Sure enough, what follows is a comparison of LED lights and fluorescent lights.

Fluorescent lamps are patented by Philips, which are currently the best lamps for daily lighting in the world.

For a more accurate comparison, the tubes of the two lamps they prepared are exactly the same, and it is almost impossible to tell which one is a fluorescent lamp from the appearance.

The lights were on and were about the same brightness, one of them seemed to be brighter, but not noticeably.

Well, go test the power.

The results came out, one of them is 36 watts, the other is 18 watts, and the 18 watt LED lights seem to be brighter.

The mystery was revealed, and the 18-watt LED lamp won again!
There was thunderous applause.

Shen Guanglin himself did not speak, and asked Jiajia to explain the principle.

"Do you know what a cold light source is? A cold light source is a light source that uses chemical energy, electrical energy, and biological energy to excite and produce light. Fireflies are cold light sources. Our LED lights are also the same."

After finishing speaking, classmate Jiajia took out a hammer and really hammered the lamp tube, which contained small lamp beads one by one.

Without the constraints of the lamp tube, the light is even brighter.

Of course, there are some knowledgeable people in the audience. They know that LED is indeed a cold light source, but the previous LEDs are all colored light. Although they have a wide range of applications, they are only used for traffic control and car taillights.

Now, with the white light source, is there anything else that can stop its development from spreading?
"It seems that everyone has also thought that the future of LED is limitless! Traditional tungsten lamps are easy to burn, heat deposition, and light decay. LEDs do not have these problems. Even compared with fluorescent lamps, the service life of our LED lamps is theirs. More than 10 times, and the power consumption of the same illuminance is less than half of theirs."

So, the revolution in lighting and display starts today.

(End of this chapter)