Japan's semiconductor industry is quite developed and well-known throughout the world. This is inseparable from the efforts of Japanese scientists. Among them, Nishizawa is one of the best. He is also known as the "Mr. Semiconductor" in Japan. According to foreign media reports, Mr. Nishizawa, a member of the semiconductor industry, died on October 21 at the age of 92. Nishizawa has made an indelible contribution to the development of Japanese semiconductors, and his legendary life will continue to affect the global semiconductor industry.
Nishizawa is one of the world's leading scientists, physicists, educators and one of the founders of Japanese semiconductor technology. In 1963, Japanese scientist Nishizawa Ryuichi proposed the concept of using optical fiber for communication. In addition, some technologies he invented, such as laser diodes, have greatly promoted the development of optical fiber communication. Mr. Nishizawa’s contributions to semiconductors:
1. Developed "PIN Diode"
Nishizawa first studied electrical engineering at Tohoku University in Japan. I heard that the United States developed a transistor and decided to study semiconductors. Finally, in 1950, he successfully developed the "PIN Diode", which is also the core achievement of his "Father of Semiconductors".
A common diode consists of a PN junction with a thin layer of low-doped intrinsic semiconductor layer between the P and N semiconductor materials. The P-I-N structure of the diode is a PIN diode. Because of the existence of intrinsic layers, PIN diodes are widely used, from low frequency to high frequency applications, mainly used in the RF field, as RF switches and RF protection circuits, and also as photodiodes.
Since Nishizawa Ryuichi developed the "PIN Diode", most of the original radio transceivers used a repeater to convert between the receiving state and the transmitting state, but this conversion efficiency is low and the distortion rate is high. Switching later with a PIN diode, the switch made up of such components does not cause signal distortion in RF, IF and audio circuits, and has become the "standard" of many RF circuits.
2. Found the principle of semiconductor laser
In the 1950s and 1960s, Nishizawa discovered that based on the principle of semiconductor lasers, semiconductor lasers are excitation methods that use semiconductor materials to illuminate between energy bands, and use the cleavage plane of the semiconductor crystal to form two parallel mirrors as mirrors. The resonant cavity is formed to amplify the light oscillation, the feedback, and the light that generates the light, and output the laser.
The semiconductor laser is a laser using a semiconductor material as a working substance. The commonly used working materials are gallium arsenide, cadmium sulfide, indium phosphide, zinc sulfide, etc. The excitation methods include three types: electric injection, electron beam excitation, and optical pumping. Semiconductor diode lasers are the most practical and important types of lasers. They are small in size, long in life, and can be pumped with a simple injection current to make their operating voltage and current compatible with integrated circuits, so they can be integrated with them.
Semiconductor diode lasers have broad application prospects in laser communication, optical storage, optical gyro, laser printing and radar.
3. Research on modern information and communication technologies
During his tenure at Tohoku University in Japan, Nishizawa was actively studying optical communication technology, discovered the principle of optical communication for optical fiber, and made great contributions to the construction of a modern information and communication technology system.
Optical fiber communication is a communication method in which light is used as an information carrier and optical fiber is used as a transmission medium. First, an electrical signal is converted into an optical signal, and then an optical signal is transmitted through the optical fiber, which is a type of wired communication.
Light can be carried after modulation, and the fiber-optic communication system has revolutionized the telecommunications industry and played a very important role in the digital age.
Due to the advantages of large transmission capacity and good confidentiality of optical fiber communication, optical fiber communication has become the most important wired communication method today.
4. Take the lead in promoting the development of silicon complete crystallization development projects
During the period of 1990-1996, Nishizawa Ryuichi served as the president of the Tohoku University, and concurrently served as the president of Iwate Prefectural University and the president of the Tokyo Metropolitan University. He trained a large number of talents for the semiconductor industry. During this period, he took the lead in the complete development of silicon and promoted semiconductors. The development of upstream materials.
Silicon crystal A crystalline silicon, grayish black, hard and brittle, boiling point 2355 ° C, stable at room temperature in air, insoluble in water and acid, but soluble in nitric acid and hydrofluoric acid mixture, hydrofluoric acid and caustic. It can be eutectic with alkali metal carbonate and can be used in the ceramic and refractory industries.
Mr. Nishizawa Junichi received the honor: Nishizawa Junyi dedicated his youth to the semiconductor industry and won many honors in his life. He has won many awards for Japanese academic and contribution, such as the Japanese Bachelor's Award, the Cultural Medal, and the First Prize. Due to his outstanding contributions in the field of semiconductor and electronic information, the International Electrical Society established the International Academic Award in his name in 2000.
In addition to receiving many honors, Professor Nishizawa also wrote a dozen monographs on educational theory and educational thoughts. In 2007, Professor Nishizawa became the president of the International Federation of Science, Technology and Engineering.
Nishizawa has left a lot of rich heritage for the Japanese semiconductor industry and even the world semiconductor industry, which is the foundation for the Japanese industry to take off. In recent years, China has vigorously developed the semiconductor industry. The author believes that we must also learn the secret of Japan's industrial prosperity, that is, attach importance to basic technology research and cultivate more scientists who are dedicated to the spirit of Nishizawa.