[[Archivo:Transistor J Bardeen W Shockley W Brattain en BellDetector a galena.jpg|500px300px|right|thumb|<small><center>'''John BardeenDetector a galena, William Shockley y Walter Brattain en su laboratorio de Bell Telephone<br>el primer dispositivo semiconductor.'''</center></small>]]La '''invención del transistor''' ('''transistor de unión bipolar''', para ser más precisos) es un caso prototípico de desarrollo combinado científico-tecnológicocolaboración entre científicos, tecnológos y empresarios. Se incluye aquí porque su historia, es decirpoco conocida, de lo que en esta enciclopedia se denomina ilustra [[tecnocienciarasgo]]. La historia es poco conocida, parcialmente debido a que involucra conocimientos no vulgares de Física de Semiconductores, parcialmente debido a la escasa comprensión que se tiene del fenómeno cultural - económico - tecnológico s y plantea interrogantes importantes sobre el proceso de la invención de [[artefacto]]s. Se incluye aquí porque permite plantear interrogantes e ilustrar aspectos de importancia para la caracterización de este proceso.

[[Archivo:Detector a galena.jpg|300px|right|thumb|<small><center>'''El primer dispositivo semiconductor usado en Electrónica fue el detector a galena consiste . Usado desde 1904 en un alambre conductor que toca un trozo los primeros receptores de galena policristalinaradio AM sencillos (por eso llamados [http://es.wikipedia.org/wiki/Radio_a_galena '''</center></small>]]El detector usado en las primeras radios a galena fue el primer dispositivo semiconductor.The first patent[1] for the field-effect transistor principle was filed in Canada by Austrian-Hungarian physicist Julius Edgar Lilienfeld on October 22, 1925, but Lilienfeld published no research articles about his devices, and they were ignored by industry. In 1934 German physicist Dr. Oskar Heil patented another field-effect transistor.[2] There is no direct evidence that these devices were built, but later work in the 1990s show that one of Lilienfeld's designs worked as described and gave substantial gain. Legal papers from the Bell Labs patent show that William Shockley and a co-worker at Bell Labs, Gerald Pearson, had built operational versions from Lilienfeld's patents]), yet they never referenced this work in any of their later research papers or historical articles.se basa en el contacto entre un alambre metálico y la superficie de una pieza de [3] The work emerged from their war-time efforts to produce extremely pure germanium "crystal" mixer diodes, used in radar units as a frequency mixer element in microwave radar receivershttp://es. A parallel project on germanium diodes at Purdue University succeeded in producing the good-quality germanium semiconducting crystals that were used at Bell Labswikipedia. [4org/wiki/Galena galena] Early tube-based technology did not switch fast enough for this rolepolicristalina (sulfuro de plomo o PbS), leading the Bell team to use solid state diodes instead. With this knowledge in hand they turned to the design of a triode, but found this was not at all easy. John Bardeen eventually developed a new branch of quantum mechanics known as surface physics to account for the "odd" behavior they saw, and Bardeen and Walter Brattain eventually succeeded in building a working device. After the war, Shockley decided to attempt the building of a triodeuna juntura metal -like semiconductor device. He secured funding and lab space, and went to work on the problem with Bardeen and Brattainque conduce bien la electricidad en un único sentido (proceso denominado rectificación).

The key to the development of the transistor was the further understanding of the process of the electron mobility in a semiconductorLa propiedad de rectificación de corrientes alternas de algunos materiales cristalinos fue descubierta en 1874 por el físico alemán [http://es. It was realized that if there was some way to control the flow of the electrons from the emitter to the collector of this newly discovered diodewikipedia.org/wiki/Carl_Ferdinand_Braun Karl Ferdinand Braun] (1850-1918), one could build an amplifierinventor del tubo de rayos catódicos y del osciloscopio, laureado con el premio Nobel en 1909 conjuntamente con [http://es.wikipedia.org/wiki/Guglielmo_Marconi Guglielmo Marconi] por el desarrollo de la radio. For instanceAunque la aplicación práctica se produjo bastante rápido, if you placed contacts on either side of a single type of crystal the current would not flow through itsu explicación demoró mucho más tiempo ya que requería saberes físicos entonces inexistentes sobre el comportamiento de los [http://es. However if a third contact could then "inject" electrons or holes into the materialwikipedia.org/wiki/Electrón electrones] (recién identificados en 1896) en átomos y moléculas. La correcta formulación matemática de estos saberes, the current would flowla [http://es.wikipedia.org/wiki/Mecánica_cuántica Mecánica Cuántica], recién comenzó en 1926 con la [http://es.wikipedia.org/wiki/Ecuación_de_Schrödinger ecuación de Schrödinger].

Actually doing this appeared to be very difficultLa Mecánica Cuántica fue inicialmente aplicada al comportamiento de los electrones de átomos e iones en estado gaseoso. If the crystal were of any reasonable size, the number of electrons (or holes) required to be injected would have to be very large -– making it less than useful as an amplifier because it would require a large injection current to start withEl mucho más complejo problema del comportamiento de los electrones en sólidos requirió varias décadas más de estudios. That saidLa explicación básica del comportamiento de los electrones en sólidos conductores, the whole idea of the crystal diode was that the crystal itself could provide the electrons over a very small distancesemiconductores y aisladores se desarrolló en las décadas de 1930 y 1940, the depletion regionaunque muchos detalles se dilucidaron posteriormente. The key appeared to be to place the input Los físicos interesados en el desarrollo histórico de los aportes principales los encontrarán en el Capítulo14, ''Rectifiers and output contacts very close together on the surface of the crystal on either side of this regiontransistors'', del libro de Dekker abajo citado.

Brattain started working on building such a device===Fuentes==* Dekker, and tantalizing hints of amplification continued to appear as the team worked on the problemA. Sometimes the system would work but then stop working unexpectedlyJ. In one instance a non; ''Solid State Physics''; Edit. Prentice-working system started working when placed in water. The electrons in any one piece of the crystal would migrate about due to nearby charges. Electrons in the emittersHall; Englewood Cliffs (New Jersey, or the "holes" in the collectors, would cluster at the surface of the crystal where they could find their opposite charge "floating around" in the air EEUU); 1962 (or water6&ordf; edición). Yet they could be pushed away from the surface with the application of a small amount of charge from any other location on the crystal. Instead of needing a large supply of injected electrons, a very small number in the right place on the crystal would accomplish the same thing.

Their understanding solved the problem of needing a very ==Desarrollo del transistor==[[Archivo:Transistor J Bardeen W Shockley W Brattain en Bell.jpg|400px|right|thumb|<small control area to some degree. Instead of needing two separate semiconductors connected by a common><center>'''Los premios Nobel de Física 1956 John Bardeen, but tiny<br> William Shockley y Walter Brattain, regionen Bell Labs.'''</center></small>]]La primera patente de un transistor, a single larger surface would serveel de efecto campo o [http://es.wikipedia. The emitter and collector leads would both be placed very close together on the toporg/wiki/Transistor_de_efecto_campo FET], with the control lead placed on the base of the crystalfue registrada en Canadá por el físico austro-húngaro [http://es.wikipedia. When current was applied to the "base" leadorg/wiki/Julius_Edgar_Lilienfeld Julius Edgar Lilienfeld] en 1925. El dispositivo, the electrons or holes would be pushed out, across the block of semiconductor, and collect on the far surface. As long as the emitter and collector were very close togethersobre el que Lilienfeld no publicó ningún informe científico, this should allow enough electrons or holes between them to allow conduction to startno parece haber sido fabricado comercialmente pero fue estudiado por los inventores del transistor de unión bipolar.

An early witness of the phenomenon was Ralph BrayThe work emerged from their war-time efforts to produce extremely pure germanium "crystal" mixer diodes, used in radar units as a young graduate studentfrequency mixer element in microwave radar receivers. He joined the A parallel project on germanium effort diodes at Purdue University succeeded in November 1943 and was given producing the tricky task of measuring the spreading resistance good-quality germanium semiconducting crystals that were used at Bell Labs. Early tube-based technology did not switch fast enough for this role, leading the metal-semiconductor contactBell team to use solid state diodes instead. Bray found With this knowledge in hand they turned to the design of a great many anomaliestriode, such as internal high-resistivity barriers in some samples of germanium. The most curious phenomenon but found this was the exceptionally low resistance observed when voltage pulses were appliednot at all easy. This effect remained John Bardeen eventually developed a mystery because nobody realisednew branch of quantum mechanics known as surface physics to account for the "odd" behavior they saw, until 1948, that Bray had observed minority carrier injection - the effect that was identified by William Shockley at Bell Labs and made the transistor Bardeen and Walter Brattain eventually succeeded in building a realityworking device.

Bray wrote: "That was After the one aspect that we missedwar, but even had we understood Shockley decided to attempt the idea building of minority carrier injectiona triode-like semiconductor device...we would have saidHe secured funding and lab space, 'Oh, this explains our effectsand went to work on the problem with Bardeen and Brattain.' We might not necessarily have gone ahead and saidBrattain started working on building such a device, 'Let's start making transistors', open up a factory and sell themtantalizing hints of amplification continued to appear as the team worked on the problem.Sometimes the system would work but then stop working unexpectedly.In one instance a non-working system started working when placed in water. At that time the important device was the high back voltage rectifier". [5]