Instruct: Given a question, retrieve relevant passages that answer the question.
Query: Who developed the first diode?
About 20 years later, John Ambrose Fleming (scientific adviser to the Marconi Company and former Edison employee) realized that the Edison effect could be used as a radio detector. Fleming patented the first true thermionic diode, the Fleming valve, in Britain on November 16, 1904[13] (followed by in November 1905).
The technique of microprogramming as first described by Maurice Wilkes in terms of a second diode matrix added to a diode matrix control store. Later computers used a variety of alternative implementations of the control store, but eventually returned to a diode matrix or transistor matrix. A person would microprogram the control store on such early computers by manually attaching diodes to selected intersections of the word lines and bit lines. In schematic diagrams, the word lines are usually horizontal and the bit lines are usually vertical.
The superluminescent diode was reported for the first time by Kurbatov et al. (1971) and Lee, Burrus, and Miller (1973). By 1986 Dr. Gerard A. Alphonse at RCA Laboratories (now SRI International), invented a novel design enabling high power superluminescent diodes. This light source was developed as a key component in the next generations of fibre optic gyroscopes, low coherence tomography for medical imaging, and external cavity tunable lasers with applications to fiber-optic communications. In 1989 the technology was transferred to GE-RCA in Canada, which became a division of EG&G. 
Superluminescent light emitting diodes are also called sometimes superluminescent diodes, superluminescence diodes or superluminescent LEDs.
Tunnel diodes are not widely used due to their low output power; their RF output is limited to several hundred milliwatts due to their small voltage swing. In recent years, however, new devices that use the tunneling mechanism have been developed. The resonant-tunneling diode (RTD) has achieved some of the highest frequencies of any solid-state oscillator. Another type of tunnel diode is a metal–insulator–metal (MIM) diode, but its present application appears to be limited to research environments due to inherent sensitivities. There is also a metal–insulator–insulator–metal (MIIM) diode, where an additional insulator layer allows ""step tunneling"" for precise diode control.
The first diode–transistor logic family of integrated circuits was introduced by Signetics in 1962. DTL was also made by Fairchild and Westinghouse. A family of diode logic and diode–transistor logic integrated circuits was developed by Texas Instruments for the D-37C Minuteman II Guidance Computer in 1962, but these devices were not available to the public.
Ohl, in 1939, discovered the PN barrier (or as it became known, the “P–N junction”). At the time hardly anyone knew anything about the impurities within these crystals, but Russell Ohl discovered the mechanism by which it worked. It was the impurities which made some sections more resistant to electrical flow than others, and thus it was the "barrier" between these areas of different purity that made the crystal work. Ohl later found that super-purifying germanium was the key to making repeatable and usable semiconductor material for diodes. All diodes (incl. LEDs, laser diodes etc.) are descendants of Ohl's work. His work with diodes led him later to develop the first silicon solar cells.
A semiconductor diode's current–voltage characteristic can be tailored by selecting the semiconductor materials and the doping impurities introduced into the materials during manufacture.[7] These techniques are used to create special-purpose diodes that perform many different functions.[7] For example, diodes are used to regulate voltage (Zener diodes), to protect circuits from high voltage surges (avalanche diodes), to electronically tune radio and TV receivers (varactor diodes), to generate radio-frequency oscillations (tunnel diodes, Gunn diodes, IMPATT diodes), and to produce light (light-emitting diodes). Tunnel, Gunn and IMPATT diodes exhibit negative resistance, which is useful in microwave and switching circuits.
Avalanche diodes These are diodes that conduct in the reverse direction when the reverse bias voltage exceeds the breakdown voltage. These are electrically very similar to Zener diodes (and are often mistakenly called Zener diodes), but break down by a different mechanism: the avalanche effect. This occurs when the reverse electric field applied across the p–n junction causes a wave of ionization, reminiscent of an avalanche, leading to a large current. Avalanche diodes are designed to break down at a well-defined reverse voltage without being destroyed. The difference between the avalanche diode (which has a reverse breakdown above about 6.2V) and the Zener is that the channel length of the former exceeds the mean free path of the electrons, resulting in many collisions between them on the way through the channel. The only practical difference between the two types is they have temperature coefficients of opposite polarities. Constant current diodes These are actually JFETs[35] with the gate shorted to the source, and function like a two-terminal current-limiting analog to the voltage-limiting Zener diode. They allow a current through them to rise to a certain value, and then level off at a specific value. Also called CLDs, constant-current diodes, diode-connected transistors, or current-regulating diodes. Crystal rectifiers or crystal diodes These are point-contact diodes.[26] The 1N21 series and others are used in mixer and detector applications in radar and microwave receivers.[23][24][25] The 1N34A is another example of a crystal diode.[36] Esaki or tunnel diodes These have a region of operation showing negative resistance caused by quantum tunneling,[37] allowing amplification of signals and very simple bistable circuits. Because of the high carrier concentration, tunnel diodes are very fast, may be used at low (mK) temperatures, high magnetic fields, and in high radiation environments.[38] Because of these properties, they are often used in spacecraft. Gunn diodes These are similar to tunnel diodes in that they are made of materials such as GaAs or InP that exhibit a region of negative differential resistance. With appropriate biasing, dipole domains form and travel across the diode, allowing high frequency microwave oscillators to be built. Light-emitting diodes (LEDs) In a diode formed from a direct band-gap semiconductor, such as gallium arsenide, charge carriers that cross the junction emit photons when they recombine with the majority carrier on the other side. Depending on the material, wavelengths (or colors)[39] from the infrared to the near ultraviolet may be produced.[40] The first LEDs were red and yellow, and higher-frequency diodes have been developed over time. All LEDs produce incoherent, narrow-spectrum light; "white" LEDs are actually a blue LED with a yellow scintillator coating, or combinations of three LEDs of a different color. LEDs can also be used as low-efficiency photodiodes in signal applications. An LED may be paired with a photodiode or phototransistor in the same package, to form an opto-isolator. Laser diodes When an LED-like structure is contained in a resonant cavity formed by polishing the parallel end faces, a laser can be formed. Laser diodes are commonly used in optical storage devices and for high speed optical communication. Thermal diodes This term is used both for conventional p–n diodes used to monitor temperature because of their varying forward voltage with temperature, and for Peltier heat pumps for thermoelectric heating and cooling. Peltier heat pumps may be made from semiconductor, though they do not have any rectifying junctions, they use the differing behaviour of charge carriers in N and P type semiconductor to move heat. Photodiodes All semiconductors are subject to optical charge carrier generation. This is typically an undesired effect, so most semiconductors are packaged in light blocking material. Photodiodes are intended to sense light(photodetector), so they are packaged in materials that allow light to pass, and are usually PIN (the kind of diode most sensitive to light).[41] A photodiode can be used in solar cells, in photometry, or in optical communications. Multiple photodiodes may be packaged in a single device, either as a linear array or as a two-dimensional array. These arrays should not be confused with charge-coupled devices. PIN diodes A PIN diode has a central un-doped, or intrinsic, layer, forming a p-type/intrinsic/n-type structure.[42] They are used as radio frequency switches and attenuators. They are also used as large-volume, ionizing-radiation detectors and as photodetectors. PIN diodes are also used in power electronics, as their central layer can withstand high voltages. Furthermore, the PIN structure can be found in many power semiconductor devices, such as IGBTs, power MOSFETs, and thyristors. Schottky diodes Schottky diodes are constructed from a metal to semiconductor contact. They have a lower forward voltage drop than p–n junction diodes. Their forward voltage drop at forward currents of about 1mA is in the range 0.15V to 0.45V, which makes them useful in voltage clamping applications and prevention of transistor saturation. They can also be used as low loss rectifiers, although their reverse leakage current is in general higher than that of other diodes. Schottky diodes are majority carrier devices and so do not suffer from minority carrier storage problems that slow down many other diodes—so they have a faster reverse recovery than p–n junction diodes. They also tend to have much lower junction capacitance than p–n diodes, which provides for high switching speeds and their use in high-speed circuitry and RF devices such as switched-mode power supply, mixers, and detectors. Super barrier diodes Super barrier diodes are rectifier diodes that incorporate the low forward voltage drop of the Schottky diode with the surge-handling capability and low reverse leakage current of a normal p–n junction diode. Gold-doped diodes As a dopant, gold (or platinum) acts as recombination centers, which helps a fast recombination of minority carriers. This allows the diode to operate at signal frequencies, at the expense of a higher forward voltage drop. Gold-doped diodes are faster than other p–n diodes (but not as fast as Schottky diodes). They also have less reverse-current leakage than Schottky diodes (but not as good as other p–n diodes).[43][44] A typical example is the 1N914. Snap-off or Step recovery diodes The term step recovery relates to the form of the reverse recovery characteristic of these devices. After a forward current has been passing in an SRD and the current is interrupted or reversed, the reverse conduction will cease very abruptly (as in a step waveform). SRDs can, therefore, provide very fast voltage transitions by the very sudden disappearance of the charge carriers. Stabistors or Forward Reference Diodes The term stabistor refers to a special type of diodes featuring extremely stable forward voltage characteristics. These devices are specially designed for low-voltage stabilization applications requiring a guaranteed voltage over a wide current range and highly stable over temperature. Transient voltage suppression diode (TVS) These are avalanche diodes designed specifically to protect other semiconductor devices from high-voltage transients.[45] Their p–n junctions have a much larger cross-sectional area than those of a normal diode, allowing them to conduct large currents to ground without sustaining damage. Varicap or varactor diodes These are used as voltage-controlled capacitors. These are important in PLL (phase-locked loop) and FLL (frequency-locked loop) circuits, allowing tuning circuits, such as those in television receivers, to lock quickly on to the frequency. They also enabled tunable oscillators in early discrete tuning of radios, where a cheap and stable, but fixed-frequency, crystal oscillator provided the reference frequency for a voltage-controlled oscillator. Zener diodes These can be made to conduct in reverse bias (backward), and are correctly termed reverse breakdown diodes. This effect, called Zener breakdown, occurs at a precisely defined voltage, allowing the diode to be used as a precision voltage reference. The term Zener diode is colloquially applied to several types of breakdown diodes, but strictly speaking Zener diodes have a breakdown voltage of below 5 volts, whilst avalanche diodes are used for breakdown voltages above that value. In practical voltage reference circuits, Zener and switching diodes are connected in series and opposite directions to balance the temperature coefficient response of the diodes to near-zero. Some devices labeled as high-voltage Zener diodes are actually avalanche diodes (see above). Two (equivalent) Zeners in series and in reverse order, in the same package, constitute a transient absorber (or Transorb, a registered trademark).
To prevent the inductive voltage pulse on turnoff, a diode is connected across the inductor as shown in fig 3. The diode doesn't conduct current while the switch is closed because it is reverse-biased by the battery voltage, so it doesn't interfere with normal operation of the circuit. However, when the switch is opened, the induced voltage across the inductor of opposite polarity forward biases the diode, and it conducts current, limiting the voltage across the inductor and thus preventing the arc from forming at the switch. The inductor and diode momentarily forms a loop or circuit powered by the stored energy in the inductor. This circuit supplies a current to the inductor to replace the current from the battery, so the inductor current does not drop abruptly, and it does not develop a high voltage. The voltage across the inductor is limited to the forward voltage of the diode, around 0.7 - 1.5V. This "freewheeling" or "flyback" current through the diode and inductor decreases slowly to zero as the magnetic energy in the inductor is dissipated as heat in the series resistance of the windings. This may take a few milliseconds in a small inductor.
These images show the voltage spike and its elimination through the use of a flyback diode (1N4007). The inductor in this case is a solenoid connected to a 24V DC power supply. Each waveform was taken using a digital oscilloscope set to trigger when the voltage across the inductor dipped below zero. In Figure 1 the voltage as measured across the switch bounces/spikes to around -300 V. In Figure 2, a flyback diode was added in antiparallel with the solenoid. Instead of spiking to -300 V, the flyback diode only allows approximately -1.4 V of potential to be built up (-1.4 V is a combination of the forward bias of the 1N4007 diode (1.1 V) and the foot of wiring separating the diode and the solenoid). The waveform in Figure 2 is much less bouncy than the waveform in Figure 1. In both cases, the total time for the solenoid to discharge is a few milliseconds.
In an ideal flyback diode selection, one would seek a diode which has very large peak forward current capacity (to handle voltage transients without burning out the diode), low forward voltage drop, and a reverse breakdown voltage suited to the inductor's power supply. Depending on the application and equipment involved, some voltage surges can be upwards of 10 times the voltage of the power source, so it is critical not to underestimate the energy contained within an energized inductor.
Phosphorescent organic light-emitting diodes (PHOLED) are a type of organic light-emitting diode (OLED) that use the principle of phosphorescence to obtain higher internal efficiencies than fluorescent OLEDs. This technology is currently under development by many industrial and academic research groups.
Following theoretical treatments of M.G. Bernard, G. Duraffourg and William P. Dumke in the early 1960s coherent light emission from a gallium arsenide (GaAs) semiconductor diode (a laser diode) was demonstrated in 1962 by two US groups led by Robert N. Hall at the General Electric research center and by Marshall Nathan at the IBM T.J. Watson Research Center. There has been ongoing debate as to whether IBM or GE invented the first laser diode which was largely based on theoretical work by William P. Dumke at IBM Labs in Yonkers, NY. The priority is given to General Electric group who have obtained and submitted their results earlier; they also went further and made a resonant cavity for their diode. It was initially speculated, by MIT's Ben Lax among other leading physicists, that silicon or germanium could be used to create a lasing effect, but theoretical analyses convinced William P. Dumke that these materials would not work. Instead, he suggested Gallium Arsenide as a good candidate. The first visible wavelength GaAs laser diode was demonstrated by Nick Holonyak, Jr. later in 1962.
Other teams at MIT Lincoln Laboratory, Texas Instruments, and RCA Laboratories were also involved in and received credit for their historic initial demonstrations of efficient light emission and lasing in semiconductor diodes in 1962 and thereafter. GaAs lasers were also produced in early 1963 in the Soviet Union by the team led by Nikolay Basov.
This diode is known by many other names, such as kickback diode, snubber diode, commutating diode, freewheeling diode, suppression diode, clamp diode, or catch diode.
In 1948, Torrey et al. stated that "It should be possible to make metal-insulator-metal rectifiers with much smaller spreading resistances than metal-semiconductor rectifiers have, consequently giving greater rectification efficiency at high frequencies". But due to fabrication difficulties, two decades passed before the first device could be successfully created. Some of the very first MIM diodes to be fabricated came from Bell Labs in the late 1960s and early 1970s Brinkman et al. demonstrated the first zero-bias MIM tunneling diode with significant responsivity. When they are using tunneling transport, the MIM diode can be very fast. As soon as 1974, this diode was reportedly used as a mixer at 88 THz in a setup of the National Institute of Standards and Technology. Thanks to recent researches the zero-bias responsivity of the MIM diode (15 A/W) is now very close to the one of Schottky diode (19.4 A/W).
In 1961 IBM started developing a low speed computer logic family that used selenium diodes with similar characteristics to silicon but cost less than one cent. The terminal development departments were begging for low cost and did not need speed. It was possible to punch eighth inch discs from a sheet of selenium diode. GE claimed they could make reliable selenium diodes. A design was achieved for a DDTL circuit with two levels of diode logic feeding one alloy transistor and no series input resistor or speed up capacitor. The family was called SMAL or SMALL for Selenium Matrix ALloy Logic. The alloy transistor proved to be too fast for the selenium diode recovery. To solve this problem a selenium diode was connected around the base-emitter to slow it down. The two level logic was similar to the PLAs Programmable logic array that would come on the market many years later. Nearly any static logic function that yielded one output could be achieved with one transistor and a handful of cheap diodes. Several years later the selenium diodes were found not to be reliable and were replaced by silicon diodes. The logic family was packaged on SMS cards.
The first EKSPLA commercial picosecond diode-pumped laser was developed in 2002. Currently (2007) the company supplies more than 20 types of diode-pumped solid-state lasers.
The Shockley diode (named after physicist William Shockley) is a four-layer semiconductor diode, which was one of the first semiconductor devices invented. It was a "pnpn" diode. It is equivalent to a thyristor with a disconnected gate.
Shockley Diodes were manufactured and marketed by Shockley Semiconductor Laboratory in the late 1950s.
Many of the advances in reliability of diode lasers in the last 20 years remain proprietary to their developers. The reliability of a laser diode can make or break a product line. Moreover, "reverse engineering" is not always able to reveal the differences between more-reliable and less-reliable diode laser products.
Of particular note is Rameyev's invention of diode-matrix control circuits, which were used to build his first brainchild, the first serially manufactured Soviet mainframe "Strela" (1954). In the 1950s, the diode-matrix control circuits were not widespread due to their significant dimensions and high power consumption. However, with subsequent development of microelectronics and the emergence of large-scale integrated circuits, which made possible to deploy tens or hundreds of thousands of diodes and transistors in a single piece of silicon, the concept of control circuits became viable and commonly used.
Such an effect was first observed in a copper–cuprous-oxide interface by Chauncey Starr in the 1930s. Beginning in 2002, theoretical models were proposed to explain this effect. In 2006 the first microscopic solid-state thermal diodes were built. In April 2015 Italian researchers at CNR announced development of a working thermal diode, publishing results in Nature Nanotechnology.
A tunnel diode or Esaki diode is a type of semiconductor diode that has negative resistance due to the quantum mechanical effect called tunneling. It was invented in August 1957 by Leo Esaki, Yuriko Kurose, and Takashi Suzuki when they were working at Tokyo Tsushin Kogyo, now known as Sony. In 1973, Esaki received the Nobel Prize in Physics, jointly with Brian Josephson, for discovering the electron tunneling effect used in these diodes. Robert Noyce independently devised the idea of a tunnel diode while working for William Shockley, but was discouraged from pursuing it. Tunnel diodes were first manufactured by Sony in 1957, followed by General Electric and other companies from about 1960, and are still made in low volume today.
GD-series germanium diodes (e.g., GD9)–this is a very old coding system OA-series germanium diodes (e.g., OA47)–a coding sequence developed by Mullard, a UK company
Normal (p–n) diodes, which operate as described above, are usually made of doped silicon or germanium. Before the development of silicon power rectifier diodes, cuprous oxide and later selenium was used. Their low efficiency required a much higher forward voltage to be applied (typically 1.4 to 1.7V per "cell", with multiple cells stacked so as to increase the peak inverse voltage rating for application in high voltage rectifiers), and required a large heat sink (often an extension of the diode's metal substrate), much larger than the later silicon diode of the same current ratings would require. The vast majority of all diodes are the p–n diodes found in CMOS integrated circuits, which include two diodes per pin and many other internal diodes.
In 1874, German scientist Karl Ferdinand Braun discovered the "unilateral conduction" across a contact between a metal and a mineral.[14][15] Indian scientist Jagadish Chandra Bose was the first to use a crystal for detecting radio waves in 1894.[16] The crystal detector was developed into a practical device for wireless telegraphy by Greenleaf Whittier Pickard, who invented a silicon crystal detector in 1903 and received a patent for it on November 20, 1906.[17] Other experimenters tried a variety of other minerals as detectors. Semiconductor principles were unknown to the developers of these early rectifiers. During the 1930s understanding of physics advanced and in the mid 1930s researchers at Bell Telephone Laboratories recognized the potential of the crystal detector for application in microwave technology.[18] Researchers at Bell Labs, Western Electric, MIT, Purdue and in the UK intensively developed point-contact diodes (crystal rectifiers or crystal diodes) during World War II for application in radar.[18] After World War II, AT&T used these in their microwave towers that criss-crossed the United States, and many radar sets use them even in the 21st century. In 1946, Sylvania began offering the 1N34 crystal diode.[19][20][21] During the early 1950s, junction diodes were developed.
Before the development of silicon semiconductor rectifiers, vacuum tube thermionic diodes and copper oxide- or selenium-based metal rectifier stacks were used. With the introduction of semiconductor electronics, vacuum tube rectifiers became obsolete, except for some enthusiasts of vacuum tube audio equipment. For power rectification from very low to very high current, semiconductor diodes of various types (junction diodes, Schottky diodes, etc.) are widely used.
The company was established at the time of the economic boom in Massachusetts. Its first successful product was the gold bonded germanium diode, widely used in computers, military equipment, etc. After that the company manufactured silicon rectifiers (which David claims were the world first ones), grown junction silicon NPN transistors, silicon diodes, germanium diodes, silicon/germanium micro-diodes, silicon references, silicon regulators, silicon controlled rectifiers, bilateral switching diodes, etc.