1883, the world-famous inventor Edison also discovered a strange phenomenon during the process of inventing the electric lamp: a piece of red-burned iron emits an electronic cloud, which later generations call it the "Edison effect". What is sad is that due to the limitations of technical conditions at that time, people did not find the practicality of this effect.
At the beginning of the 20th century, cable telegram was released. This invention has brought a lot of convenience to people. The signal generated by the wired telegram is a high-frequency radio wave, and the receiving station must rectify it in order to hear the sound from the receiver. At that time, the rectifier had a complex structure and poor efficacy, so it needed to be improved urgently. At this time, a British inventor named Fleming was studying high-frequency rectifiers. He thought, what would happen if the "Edison effect" was applied to the detector ?
In 1904, Fleming added a plate in front of the electric wire (filap) heated in a vacuum, and invented the first electron tube . He called this type of electron tube with two poles diode . Using the newly invented electronic tube, the current can be rectified to make the telephone receiver or other recording device work. Nowadays, when we open an ordinary tube radio , we can easily see the tubes burning red with the filament. It is the heart of electronic equipment work and the starting point of the development of the electronic industry.
Fleming's diode is a brand new invention. It works very well in the laboratory, but for some reason, it is not as reliable as the ore detectors that were invented at the same time. Therefore, the secondary tube did not have any impact on the development of radio at that time.
Shortly thereafter, American inventor De Forrest cleverly added a gate between the diode's filament and the plate pole, thus inventing the first vacuum transistor. This small change actually brought unexpected results. It not only has more sensitive responses, can produce sound and vibration, but also integrates three functions: detection, amplification and oscillation. Therefore, the invention of transistor is regarded as the true starting point for the birth of the electronics industry. De Forrest himself was also very surprised, thinking that "I discovered an invisible air empire." The invention of
electronic tube has promoted the vigorous development of radio electronics. By around 1960, the radio industry of Western countries produced 1 billion radio tubes annually. In addition to being used in telephone amplifiers, sea and air communications, electronic tubes have also penetrated widely into the field of home entertainment, broadcasting news, educational programs, literature and music to thousands of households. Even the invention and further development of aircraft, radar , and rockets have the power of electronic tubes.
faces challenges and finds a different approach
Since its birth, electronic tubes have been in the scientific territory and are active in various fields of electronic technology. Using it with electronic computers is like a tiger adding wings, with unprecedented speeds of computing, liberating people from the complex and distressing mechanical operations. However, during use, some of its own weaknesses gradually exposed.
first, short service life. It usually costs thousands to ten thousand hours, and it is easy to use on telegrams, radios, and TVs. Because in this type of electrical appliance, electronic tubes are not used many times. On a machine, there are only three or five to ten, but in electronic computers, the situation is completely different. In an electronic computer, thousands of electronic tubes are often needed. If there is a problem, the entire computer will be "diseased". If a certain electronic tube dies, it will be difficult for scientists to find out at once and determine which electronic tube should be replaced. If the whole body is "major blood exchange", the cost will be very heavy.
second, consumes a lot of power. Electronic computers use electronic tubes in large quantities, and they are only veritable " electric tiger ". The power delivered by a battery or small generator , etc., cannot meet the electricity needs of electronic computers, so electronic computers cannot be used outdoors.
Third, huge in size and extraordinary weight. Due to the large amount of power consumption and the huge amount of heat emitted by electronic computers, a computer must also be equipped with a bloated and bulky heat dissipation device.
Fourth, the jade body is fragile, glass tube will break if it is touched slightly.If it is hit hard, the entire computer will fall apart.
The advantage of electronic computer "superior calculation" was unfortunately greatly reduced by the weakness of its heart component - the electronic tube, and its development is naturally severely restricted.
1895, after the invention of wireless telegraph, many people conducted repeated experiments to improve the metal chip detector in the receiver. It was not until 1906 that people invented ore detectors. Different from metal chip detection, although its conductivity is far inferior to metal chips, its detection performance is worse than metal chips. Why? This has caused many people to actively study semiconductor material . However, the performance of natural ore detectors is not stable, and soon it gives way to a vacuum diode with better performance. semiconductor was then stamped into the "cold palace". However, semiconductors still retain a small position in the radio territory - the selenium rectifier of copper oxide rectifier.
In the 1930s, due to the development of radio, television and radar, "microwave" began to be used in communications. The current frequency of the microwave is surprisingly high, which makes the electron flow in the vacuum diode unable to keep up with the pace of signal change, which forces people to re-invigorate the ore detector abandoned in the "cold palace". However, the detection properties of natural ores are unstable, so it is really difficult to take on this important task. Scientists have to do some in-depth research on it to find out its mystery.
1940, a semiconductor diode with excellent performance, which was launched. It has stable performance and can work at very high frequency. It is obviously better than vacuum diodes. So, what is the difference between artificial ore and natural ore? It turns out that natural ore contains too many impurities and is not high in purity, which greatly reduces the performance of semiconductors. Smelting and crystallization technology can remove impurities in natural ores and produce extremely high purity semiconductors - germanium, silicon, etc.
Furthermore, people have realized that since electronic transistors can be generated based on electronic diodes, it is natural that semiconductor transistors should be developed based on semiconductor diodes.
A brand new history was born!
Knowing the difficulties, "Baby" was born
Research new electronic devices. At that time, the famous solid physicist Shockley proposed to use semiconductors as the research direction. As early as 1925, scientists discovered the field effect characteristics of semiconductors, that is, applying an electric field at both ends of a semiconductor will change the concentration of charge in the semiconductor, thereby changing the conductivity of the semiconductor. After graduating from the Department of Physics at Caltech, Shockley entered MIT to obtain a PhD in physics, and then entered Bell Labs in 1936. He has been engaged in the research on solid physics , wanting to figure out the material structure of field effects and infer that the field effect can be used for signal amplification. He once tried to make field effect devices with experimental master Bratton, but it completely failed.
In the summer of 1945, Bell Labs decided to set up a special research team to figure out the mechanism of semiconductors and explore the possibility of using semiconductors to make amplifier .
In January 1946, the Solid Physics Research Group of Bell Laboratory was officially established. This group is headed by Shockley and has several groups under its jurisdiction, which are active in many disciplines and aspects. They worked together and were full of enthusiasm to fully devote themselves to the research and exploration of the field of theoretical physics . Starting from
, Bratton and Badin used the field effect concept proposed by Shockley when studying transistor . Field effect concept is the specific solution for the first solid amplifier proposed by people. According to this scheme, they modeled the principle of vacuum transistors and tried to use external electric fields to control the motion of electrons in the semiconductor. But things went against my expectations, and the experiment failed repeatedly. People get much smaller effects than expected. After many sleepless nights of thought, Badin proposed a new theory - the theory of surface states. This theory believes that surface phenomena can cause signal amplification effects. The introduction of the concept of surface state has taken a big step forward in people's understanding of the structure and properties of semiconductors.Bratton and others took advantage of the victory and conducted a series of experiments carefully and meticulously. As a result, they unexpectedly discovered that when the sample and reference electrode were placed in electrolyte , the charge layer inside the semiconductor surface and potential changed, which was exactly the "field effect" that Shockley once predicted.
Everyone was extremely excited and accelerated the research pace and repeatedly conducted experiments using the field effect. Unexpectedly, a completely different effect suddenly occurred during the continued experiment, and the situation became confusing again.
However, Shockley's group insisted on facing difficulties. They followed a ray of light in the vast fog, changed their thinking and continued to explore. After many analysis, calculations and experiments, on December 23, 1947, people finally got the long-awaited "baby". On this day, Badin and Bratton placed the two contact wires on the surface of the germanium semiconductor wafer. When the two contact wires were very close, the amplification effect occurred. The world's first solid amplifier, crystal transistor , was also born, which is exactly what people are used to call "transistor".
The transistor that Bardin and Bratton successfully experimented is a certain point contact between a metal contact wire and a semiconductor, so it is also called a point contact transistor. This kind of transistor has an amplification effect on current and voltage. The emergence of
transistors is a colorful quirky flower blooming on the tree of electronic technology. Compared with electron tubes, transistors have many advantages: first, the components of the transistor are not consumed. No matter how good an electron tube is, it will gradually deteriorate due to changes in cathode atoms and chronic air leakage. Due to technical reasons, the same problem existed at the beginning of transistor production. With the advancement of material production and improvements in many aspects, the lifespan of transistors is generally 100 to 1,000 times longer than that of electron tubes, which deserves the reputation of "permanent devices".
Second, the transistor consumes very little electrons, only one tenth or a few tenth of the electron tube. It does not require heating the filament like the electron tube to produce free electron . A transistor radio can be listened to for half a year with just a few batteries, which is difficult for electronic tube radios.
Third, the transistor does not need to be preheated and works as soon as it is turned on. For example, the transistor radio will ring as soon as it is turned on, and the screen will appear quickly as soon as the transistor TV is turned on, and the electronic tube device cannot do this. After turning on, you have to wait for a while before you can hear the sound and see the painting. Obviously, transistors have very advantages in military, measurement, recording, etc.
Fourth, the transistor is strong and reliable, 100 times more reliable than the electron tube, and it is resistant to shock and vibration, which are incomparable to electronic tubes.
In addition, the transistor is only one tenth to one percent of the volume of the electron tube, and has very little heat release, which can be used to design small, complex and reliable circuits. The transistor manufacturing process is precise and the process is simple, which is conducive to improving the installation density of components.
Because of the superior performance of transistors, transistors quickly replaced electronic tubes in many fields after their birth and were widely used in industrial and agricultural production, national defense construction and people's daily lives. Show off your powers in almost all electronic fields such as TV, radar, audio recorders, video recorders, wireless telephones, etc. In 1953, as soon as the first batch of battery-type transistor radios were put on the market, they were warmly welcomed by people, and people rushed to buy these radios. Then, a competition was launched among various manufacturers to manufacture short-wave transistors. Shortly thereafter, the pocket "transistor radio" that did not require AC power began to be sold around the world, causing a new consumption boom. #Telebrity Creation Challenge#
Since Fleming invented the vacuum diode in 1904 and DeForrest invented the vacuum transistor in 1906, Electronics has developed rapidly as an emerging discipline. However, the real rapid progress in electronics should have begun after the invention of transistors. In particular, the emergence of PN junction transistors opened up a new era of electronic devices and caused a revolution in electronic technology.In just over ten years, the emerging transistor industry has quickly replaced the position that the electronic tube industry has achieved through years of struggle with its invincible ambition and the unscrupulous momentum of young people, and has become the vanguard in the field of electronic technology. #Popular Science#
