Tungsten is inseparable from transistors
Since the advent of transistors, tungsten has been an insoluble bond. The so-called transistor is a kind of variable current switch, which is different from the ordinary mechanical switch. It uses telecommunication signal to control its switch, and the switching speed can be very fast. In the laboratory, it can even reach the switch speed above 100GHz. It is small and is usually part of a computer, cell phone, or other electronic device. With the advent of transistors, large power-consuming tubes can be replaced by low-power electronic devices. Transistor is regarded as the greatest invention of electronic technology in the 20th century. It triggered the microelectronic industrial revolution and laid the foundation of modern civilization. Later, the invention of transistors led to the birth of integrated circuits. The invention of the transistor dates back to 1929, when engineer Lillionfield patented a transistor. However, due to the level of technology at the time, the material used to make the device was not pure enough to make transistors. It was not until 1945 that Bell Labs was founded by the WW. b. Shockley led the semiconductor research group, led by experimental physicist w. h. Bratton and g. l. Pearson leader, physical chemist R. Gibney and circuit expert H. Moore and theoretical physicist J. Pattin leads. Soon after the establishment of the research group, membersundefined research focus shifted from the development of field effect amplifiers to the basic theoretical problem of semiconductors, namely, the study of surface states. The surface state problem is the basis of the field effect amplifier experiment. After more than a year of repeated tests, the team finally confirmed the existence of the surface state effect in September 1947. It is further found that the surface state effect can be enhanced or weakened by injecting liquid containing positive and negative ions, such as water, between the electrode plate and the surface of silicon crystal. On November 21, 1947, Bardin suggested to Bratton that he should begin experiments with semiconductor amplifiers. The experiment was carried out on the same day, and a weak amplification current signal was observed in the output loop. However, their voltage gain is very small and can only work at an ultra-low frequency below 10 Hz, and the actual amplifier must be able to amplify the input signal in kilahertz units. On December 11, 1947, Gibney provided an n-type germanium sheet with an oxide layer (used to replace the electrolyte) on which five small gold particles were deposited. Bratton used germanium crystals as electrodes in gold particles and small holes inserted tungsten wires through holes and oxide layer germanium crystals, hoping to change the conductivity between tungsten wire electrodes and germanium crystals by changing the voltage between gold particles and germanium crystals. The results show that the resistance of gold particles to germanium crystals is very small.
Still, Bratton decided to try some experiments. In one experiment Brahton accidentally applied a negative voltage to the tungsten wire and a positive voltage to the gold particle without expecting the output signal to be opposite to the input signal. Initial test result: voltage magnification factor is 2, upper limit frequency can reach 10 kHz. This means that there is no need to make a special oxide film on the surface of germanium crystal, and a good response frequency can be obtained by direct contact between the gold particles and the surface of the germanium crystal. Bardin is acutely aware of a new physical phenomenon at the interface of gold-germanium crystals, which is completely different from the addition of electrolyte. The key is to make the tungsten contact point of germanium crystal surface as close as possible to the metal electrode. Bratton and technicians quickly developed an experimental device that met the requirements of bardin and carried out the first improved experiment with bardin on the afternoon of December 16. In this experiment, they obtained 1.3 times output power gain and 15 times output voltage gain. Therefore, some scholars believe that this day should be set as the invention day of transistors. Tungsten is also connected to transistors. A week later, on December 23, Shockleyundefineds semiconductor team demonstrated to Bellundefineds supervisor the audio amplification experiment, which included a newly invented solid-state amplifier. This is an audio amplification experiment without an electron tube. The experiment was as successful as expected. The team later named the solid-state amplifier "transistor" in Chinese. The transistor is called bipolar contact transistor because it consists of two conductors and semiconductor point contact. On June 17, 1948, the patent attorney of Bell telephone Laboratory completed the patent application for the point contact transistor. On June 23, Bell showed his transistor demonstration device to the US military representative, and the device was finally approved for public release. Meanwhile, Shockley and Pearson, Barding and Bratton all co-authored a set of physical commentaries describing transistors and how they work. After all the preparatory work, Bell held a press conference on June 30 at the headquarters building to announce the worldundefineds first transistor. Since then, the transistor sparks that Barding and Brighton ignited in 1947 began to form. Recently, a team of researchers at Columbia Universityundefineds School of Engineering synthesized a new molecule that prevents leakage of current, potentially making transistors larger than their physical limits. At present, the transition metal tungsten disulfide and tungsten selenide have become a new research hotspot in the next generation computer transistors because of their special layered structure and excellent electrical, optical, plasma, electrochemical and electrocatalytic properties.
