Gan Zizhao: practice and exploration of GaN based LED research

China's semiconductor lighting industry is developing rapidly. In this case, we must pay attention to draw lessons from history. After the history of reform and opening up, many of our emerging industries is not too late to start, but because there is no joint, and finally behind, such as optical fiber communications. Hope that under the joint efforts of everyone, the establishment of the laboratory can really play a role in learning lessons for the failure, bigger semiconductor lighting. I hope we will do it with a sense of responsibility, and strive for breakthroughs in core technologies. In the August 2011 meeting of the National Key Laboratory of semiconductor lighting joint innovation (chips) work conference, academician Gan Zizhao on the future development of the semiconductor lighting industry has raised ardent expectations.

In the early 90s of last century, when he was head of the Department of physics,, led the research team began the development of GaN based blue LED, and achieved important results, and participated in the early industrialization. Selected from research direction to participate in the production practice, the road is full of hardships, in carrying out the study of GaN based LED also witnessed China semiconductor lighting "development process from scratch, from small to large.

The passage of time, although not in the scientific research, but Gan Zizhao has been concerned about the industry, concerned about the development of the industry. Today, semiconductor lighting has made great development, but in the academician Gan Zizhao, now is not "juan", industry development is still facing difficulties and challenges, the industry needs to be rational and alert.

The study of "passivity"

"Holding the mentality of trying, we started the development of nitride led. It can be said that the Department of physics in the north to carry out the work, began to be some passive. Academician Gan Zizhao recalls.

Research in the field of Semiconductor Physics Department of Peking University has a long history, its development shows that in 1956, according to the needs of national scientific development planning, Peking University, Fudan University, Nanjing University, central Xiamen University, Jilin University five school teachers and students to the Physics Department of Peking University, Huang Kun (one of the world famous physicist, China solid and semiconductor physics founder), Xie Xide the professor (a famous physicist and educator in China, one of the pioneers of Semiconductor Physics) under the auspices of the founder of China's first professional semiconductor. Two hundred students founded in three years after the train has become China's first batch of new semiconductor business backbone, the important role of China from the establishment and development of the semiconductor industry of science and technology system.

In early 90s, on semiconductor research university physics department director, academician Gan Zizhao, Department of Peking University, then relying on Artificial Microstructure and mesoscopic physics laboratory started construction, obtained some scientific research funds. At that time, the funds are still very small, we decided to come up with some of the funds from the purchase of MOCVD equipment to do some compound semiconductor research, the purchase is the Chinese Academy of Sciences, Changchun Institute of independent research and development of MOCVD equipment. "For the circumstances, academician Gan Zizhao fresh, accompanied by the arrival of the equipment, equipment for the participation of Zhang Guoyi (Professor of physics Peking University) also a postdoc at Peking University Department of physics.

However, after the arrival of equipment, the research direction is still in suspense, "originally intended to do research on GaAs, but at that time the Department whether the level of equipment or financial strength are difficult compared with the Chinese Academy of Sciences and semiconductor physics, they are the real force of GaAs is more powerful, so we are not suitable to do research" the academician Gan Zizhao said, this also means that the need to find the right direction.

From the international background at that time, at the end of 1980s and early 90s, Japan's Nakamura Shuji has started to research the blue light emitting diode, the results have also been reported, among them, in 1992 the production of double heterojunction GaN light emitting diode, and confirmed that light, high brightness of the same year to achieve double heterostructure light emitting diode GaN the.

To understand some of Nakamura Shuji's research department, some comrades found Gan Zizhao, "the comrade came to me and said this is a direction may try, the comrades specially copied to the report material. "Although from some point of view, Gan sample is not good, the dislocation density is high, while the luminous efficiency is good, the comrades of the recommendations to the academician Gan Zizhao's attention, he found the specific responsible comrades to discuss, but also sought the views of Zhang Guoyi, try holding the mentality, Peking University Physics Department started Gan the research work based blue light emitting diodes. It can be said that the Department of physics in the north to carry out the work, began to be some passive, recalled the beginning of this experience, Gan Zizhao academician said with a smile.

When there are no international red, white, and Huang Lvguang have been prepared, but the lack of blue light, and Blu ray, the international popular argument is the 26 materials prepared by Gan system is a new method of preparing blue. In the north of the Department of physics began to study the preparation of gallium nitride blue light-emitting diode, the international literature reports also slowly up. "Gan samples of inferior quality GaAs, while the luminous efficiency is very high, this is a scientific question, then do the research, beginning with the production and not what relationship, just as the foundation of. Gan Zizhao