On February 3, 2016, General Secretary Xi Jinping came to Nanchang University in Jiangxi and inspected the National Silicon-based LED Engineering Technology Research Center Laboratory. The "Silicon Substrate Blue Light-Emitting Diode" project led by Professor Jiang Fengyi in this laboratory won the first prize of National Technology Invention Award in 2015.
General Secretary Xi Jinping listened to the introduction of the laboratory's research results, inspected the chip production process, and learned about the laboratory's scientific and technological innovation, talent training, industry-university-research integration, etc., and visited the Nanchang Optics Valley exhibition hall, affirming their efforts in solving scientific research problems and transforming results. Determination is strong, goals are high, work is practical, and results are good. General Secretary Xi Jinping pointed out that the process of mastering core technologies is difficult, but this path must be taken.
At 8 o'clock in the morning, we went to the office of the National Silicon-based LED Engineering Technology Research Center to interview Jiang Fengyi, but we came to nothing. His students told us: "You are looking in the wrong place. Teacher Jiang rarely stays in the office."
This research center is located in Nanchang High-tech Zone. It has 6 laboratories including equipment manufacturing, material growth, and chip preparation on three floors. "Wherever there is a problem that cannot be solved, the teacher will appear there. You can only call his mobile phone."
The mobile phone was connected, and a mandarin with a Jiangxi accent came from the other end: "I am a metal organic man on the first floor. The chemical vapor deposition (MOCVD) equipment room is very busy today! "
Jiang Fengyi works in the laboratory in Nanchang High-tech Zone (photo taken on August 5, 2022). Photographed by Xinhua News Agency reporter Zhou Mi
Walking into the laboratory, 7 MOCVD equipment are neatly arranged. They are key material manufacturing equipment for semiconductor lighting chips. In front of the largest equipment, a man of medium height wearing a white dust-proof suit was giving instructions.
The device indicator light flashes one after another, and the data on the console screen keeps changing. "When doing experiments, you have to keep trying and making mistakes." The person doing the explanation raised his voice. He is Jiang Fengyi.
59-year-old Jiang Fengyi is an academician of the Chinese Academy of Sciences and vice president of Nanchang University, but he prefers others to call him "Teacher Jiang" - he likes this title.
We called "Teacher Jiang". He waved us to sit down next to him: "Wait a minute. Our yellow LED experiment is encountering a problem at the moment."
Light-emitting diode, referred to as LED in English, is a commonly used light-emitting device. Yellow LED is the key core technology that Jiang Fengyi has been focusing on in recent years. It does not require rare earth phosphors and has no blue light hazards. It is regarded as an artificial lighting source that may replace the current "blue LED + rare earth phosphors".
did not expect that the wait would last for several hours. After walking around the laboratory, we followed Teacher Jiang into the office on the third floor.
Teacher Jiang took off his dustproof suit, and his white shirt was soaked with sweat. "How good the scientific research conditions are now!" He pointed out the window, "We moved from the Nanchang University campus to the High-tech Zone. This experimental building has nearly 9,000 square meters. When we first started, the laboratory only had 60 square meters, and we borrowed 600,000 yuan. Yuan bought equipment and started researching blue LED. "
Jiang Fengyi works in the laboratory in Nanchang High-tech Zone (photo taken on August 5, 2022). Photo by Xinhua News Agency reporter Zhou Mi
Draw the curtains and turn on the lights in the room, and the conversation begins with the "light" filling the room.
"This ceiling chandelier was developed here. It mainly uses red and yellow light that are more comfortable for human eyes." Teacher Jiang started "classes": from kerosene lamps, incandescent lamps , fluorescent lamps to blue LEDs, lighting has been done again and again before Technology is defined abroad.
"For example, kerosene lamps were called foreign oil lamps because the lamp oil was imported at that time. LED lighting technology also made breakthroughs abroad, but we can't keep lighting foreign LED lamps!"
Blue-light LEDs, which are widely used today, were at the core of the early 2000s. Patents are also monopolized by foreign countries. This deeply hurt Jiang Fengyi.
He decided to find another way and chose to grow materials on silicon substrates to make chips.This process involves many procedures, with more than 70 layers in the material structure alone, more than 100 steps in the growth procedure, and more than 2,000 parameters involved.
"Every parameter is a variable, and every adjustment is a trial and error. Finding the optimal solution requires thousands of trials and errors," he said.
Jiang Fengyi has been on this road of "chasing the light" for 19 years. He successfully developed silicon substrate blue LED materials and chip technology, making my country the third country in the world with independent intellectual property rights in blue LED technology.
turned on a cylindrical lamp on the table, and soft yellow light spread on the table. Teacher Jiang patted it happily: "This is golden LED, a better and more difficult LED lighting technology!"
In 2011, while focusing on blue LED, Jiang Fengyi has set his sights on yellow LED. However, in front of domestic and foreign researchers, there is a "yellow light gap" - the light efficiency of yellow light is significantly lower than that of blue light, and the light efficiency is difficult to exceed 10%.
Opening the drawer, Jiang Fengyi took out a thick stack of diaries, which recorded every day's scientific research progress. He has maintained this habit for nearly 30 years.
In the 1990s, the research on strained superlattice structures jointly completed by professors Pan Chuankang (middle), Jiang Fengyi (right) and Zheng Daiqiu of Nanchang University achieved significant results. Their pioneering ion beam channel layered scanning technology improved the measurement accuracy by an order of magnitude, which was the leading international level at the time (data photo). Photo by Xinhua News Agency reporter Song Zhenping
Opening the top diary, under the number "9.4%" on the page, Jiang Fengyi drew several lines: "This is a hurdle."
At that time, the laboratory had 4 MOCVD equipment . Jiang Fengyi took out 3 units for blue light and 1 unit for yellow light. "The investment is huge and the future is unknown. I dare not move too fast."
However, the yellow light effect produced by this machine stopped at 9.4%.
"I hesitated at the time, wondering if this road would work?" Jiang Fengyi turned back the diary.
The diary contains mostly one page of scientific research data per day. But on February 3, 2016, Jiang Fengyi wrote five dense pages. What he wrote down were the scenes and instructions given by General Secretary Xi Jinping during his inspection.
"We decided to take out 3 pieces of equipment to make yellow light, let's get started!" Jiang Fengyi stood up and rummaged through the documents in the cabinet for us, "Look, there is more support from the country, and there are also support policies from the province and city. , catching up with such a good time, what excuse do we have for not working hard? "
Jiang Fengyi and his team "nailed" it in the laboratory. If you are hungry, eat a lunch in the laboratory; if you are tired, find a place to take a nap. "I haven't been out of the building for a week at most," he said, pointing to the bed in the room.
Jiang Fengyi works with team members in the laboratory located in Nanchang High-tech Zone (photo taken on August 5, 2022). Photo by Xinhua News Agency reporter Zhou Mi
html After 140 days, the light efficiency broke through the "yellow light gap" and reached 12.2%. But later, this value stopped moving.
"I know that this gap is not that easy to bridge!" Teacher Jiang paused here. "After thinking about it, I proposed to change the equipment! I used imported MOCVD equipment to perform surgery. After hearing this, everyone said that I was too bold. "
For more than a month, he led two equipment experts and a group of engineers to work overtime and made 6 major changes and more than 10 minor changes to significantly improve the performance of MOCVD.
On May 5, 2016, after nearly a hundred days of research, Jiang Fengyi came to the laboratory early in the morning. Everyone was staring at the screen, and the test results of chips and devices manufactured by new equipment came out - 17.2%!
Some students shouted. Jiang Fengyi, who had always been reserved, also clapped his hands happily.
"At 12%, I was still unsure. When it reaches 17%, it shows that this path is feasible."
What did you write in your diary that day?
"2016-05-05, the result: the light efficiency reached 17%... If further optimized, there is hope to reach more than 25%..."
Guessing what we were thinking, Teacher Jiang said: "I think General Secretary Li is right We are still far from what we were told, so we cannot be proud."
21.4% on October 26, 2016, 24.3% on July 16, 2018, 27.9% on November 25, 2020... The yellow light efficiency has broken through again and again, constantly setting world records.
Jiang Fengyi's road to "chasing light" is still there. In the past two years, they have continuously improved the light effect of yellow light and accelerated the transformation of results. Standing up and looking out the window, Lao Jiang pointed to the golden landscape lights of Aixi Lake Park not far away and said, "That is our golden light. LED has achieved mass production. "
It was getting dark, and we stood up to say goodbye. "I can't keep you for dinner today. "Jiang Fengyi shook hands with us apologetically and revealed good news, "We have made another big breakthrough in yellow light. The maximum light efficiency at a specific working point is over 50%! "
Jiang Fengyi sent us downstairs and saw six big red characters written on the wall of the research center hall: more light, less heat.
He stopped specifically and said: "This sentence has three meanings: First, in the field of LED , if you want to shine more, you must generate less heat; second, in dealing with people, you must concentrate on doing things and be less hot-headed; third, in scientific research, you must endure loneliness and join in the fun less. "
Waving goodbye, Jiang Fengyi turned around and walked into the laboratory again.
Text reporters: Guo Qiang, Yu Xianhong
New media editor: Wu Jinfu
