Invention of the Transistor Summary

  • Last updated on November 10, 2022

The development of the transistor gave birth to a new era of solid-state electronics. In addition to making telephone relaying technology more efficient, the device made possible a host of mass-marketed consumer electronics devices, from the transistor radio to the personal computer.

Summary of Event

The invention of the transistor in December, 1947, revolutionized the fledgling electronics industry and paved the way for a postwar explosion in communications and computer technology. The invention of the transistor was also one of the most significant productions of industrial scientific research laboratories, first established by the electrical and chemical industries to organize and direct the process of scientific research toward the needs of the sponsoring corporations. Transistors;invention Electronics [kw]Invention of the Transistor (Dec. 23, 1947) [kw]Transistor, Invention of the (Dec. 23, 1947) Transistors;invention Electronics [g]North America;Dec. 23, 1947: Invention of the Transistor[02200] [g]United States;Dec. 23, 1947: Invention of the Transistor[02200] [c]Inventions;Dec. 23, 1947: Invention of the Transistor[02200] [c]Communications and media;Dec. 23, 1947: Invention of the Transistor[02200] [c]Science and technology;Dec. 23, 1947: Invention of the Transistor[02200] [c]Engineering;Dec. 23, 1947: Invention of the Transistor[02200] Bardeen, John Brattain, Walter H. Shockley, William De Forest, Lee Kelly, Mervin J.

The Bell Telephone Laboratories Bell Telephone Laboratories (Bell Labs), which produced the transistor, were first established in 1925 to serve the research and development interests of their co-owners, the American Telephone and Telegraph Company and the Western Electric Company. The Bell laboratories were systematically organized into research sections, each concentrating on an aspect of the communications industry. Their primary corporate goal was the improvement and expansion of existing communications equipment.

Before the invention of the transistor, the expansion of the telephone Telecommunications;telephony system had depended on the vacuum tube. The main problem in sending telephone messages over long distances was that the signal lost its strength as it traveled, so that the message became increasingly faint. The invention of the three-element vacuum tube (triode) in 1906 by a young inventor, Lee de Forest, had permitted the amplification and reamplification of the voice signal; with further improvements, the vacuum tube had made possible the first transcontinental telephone call between New York and San Francisco in 1915.

By 1936, Mervin J. Kelly, director of research at Bell Labs, had become concerned about the limitations of the vacuum tube. Long-distance telephone transmission required huge numbers of vacuum tubes as amplifiers. These tubes had serious drawbacks: They were fragile, bulky, gave off too much heat, consumed too much electrical power, and failed frequently, disrupting service. Because the tubes did not last very long, circuits that used a great many of them were costly to operate and maintain. As a result, Bell Labs hired scientists and engineers explicitly to form a special interdisciplinary solid-state Solid-state electronics[Solid state electronics] research team to develop a better technology.

Kelly approached a young physicist working at Bell Labs, William Shockley, with the problem of finding a cheap and efficient replacement for the vacuum tube. Shockley had been working on semiconductors Semiconductors Conductivity, electrical , which he thought might have the potential for amplifying electrical signals. (Semiconductors, such as germanium and silicon, have conduction properties intermediate between those of insulators, such as glass, and conductors, such as copper.) Shockley began exchanging ideas with Walter H. Brattain, another young Bell Labs physicist, who also had been working with semiconductors. World War II interrupted their research, however, and it was not until late in 1945 that they were able to return to the problem. After the war, they were joined by John Bardeen, one of Bell Labs’ theoretical physicists. The three decided to begin their investigations with germanium and silicon, two semiconductor solids that had been widely used during the war for signal detection.

Shockley and Brattain tried to understand why the semiconductors allowed current to flow at points of contact with certain other metals. Shockley thought that the electrical fields set up by the current at these points of contact might be made to control the amount of current flowing through the semiconductor. If so, a small electrical charge at the contact point could be made to generate a large current in the semiconductor, thus producing amplification.

The team’s first experimental device consisted of a tiny slab of germanium mounted close to, but insulated from, a piece of metal. It failed; it continued to fail, despite many design changes. Following these failures, John Bardeen developed a theory explaining the peculiar movements of electrons on the surface of a semiconductor. In an absolutely pure state, a crystal of germanium does not easily carry an electric current, because of the stability of the electron-sharing pattern (covalent bonds) between germanium atoms. If an impurity is present, however, this electron-sharing pattern is altered. Depending upon the atomic structure of the impurity, various numbers of electrons are freed to migrate whenever an electrical charge reaches the crystal. This electron movement allows the electrical current to flow across the germanium without changing its structure.

When Bardeen had formulated the solid-state theory, Brattain began experiments to confirm it. Months of experimenting went by, as the team pursued what Shockley came to call the “creative failure methodology.” On November 17, 1947, the last phase of discovery began. Following the suggestion of colleague Robert B. Gibney Gibney, Robert B. , Shockley, Brattain, and Bardeen tried generating an electrical current perpendicular to the semiconductor. They set their germanium crystal in contact with two wires two-thousandths of an inch apart. When the current reached the semiconductor, it amplified more than forty times. The “transistor effect” had been discovered. (The word “transistor” is short for transfer resistor, because the circuit transfers current from a low-resistance circuit to a high-resistance circuit.)

By December 23, 1947, the three men were ready to demonstrate a working model to their colleagues. Their little device looked primitive. Bardeen had pressed two tiny strips of gold leaf, to act as contacts, onto a germanium crystal, which he then put on top of a piece of metal. This was the first transistor. It was a solid-state device, because it had neither moving parts nor a vacuum. It was therefore capable of bypassing the limitations of the vacuum tube.

For six months, the invention was kept secret while improvements were made and patents were drawn up. On July 1, 1948, Bell Labs reported the discovery. The unheralded announcement went virtually unnoticed by the general public. After an initial period of concern over the cost involved in switching production technology, the electronics industry ultimately responded.


Impure semiconductors can be of a positive or negative charge type. Shockley’s subsequent sandwiching of minuscule impure semiconductors with a piece of one type in between pieces of the other type yielded the junction transistor in 1951; it proved to be more useful. In the early days, both kinds of transistors were limited in their applicability, easily damaged, unreliable, and expensive. Development of techniques to manufacture semiconductor materials of sufficient purity would require time and money.

In 1952, when Bell first offered the developed transistor in a licensing arrangement, all the major vacuum tube manufacturers took out licenses and soon began production. Realizing the potential of the device for military electronics, the Department of Defense sponsored further research, development, and production of transistors. Private capital was injected into the field as well, leading to new types of junction transistors with new materials such as silicon; transistors for specific applications, such as power transistors; and somewhat different technology in several types of field effect transistors. Transistors were used not only in the telephone network but also in radios, recorders, computers, calculators, instrumentation, and medical electronics; new, unexpected products hit the market. Transistor production became internationalized, with both the devices themselves and whole systems being made overseas; it opened up the Japanese consumer electronics industry. Further development led to integrated circuits that could combine millions of transistors on a single chip.

Creation of the point-contact transistor resulted in the awarding of the Nobel Prize in Physics Nobel Prize in Physics;John Bardeen[Bardeen] Nobel Prize in Physics;Walter H. Brattain[Brattain] Nobel Prize in Physics;William Shockley[Shockley] to the three Bell Labs scientists, Bardeen, Brattain, and Shockley. As a result of the transistor, all electronic products could be made much smaller, could run on much less power, and could be made much more cheaply. A new sector of technology was built on the tiny crystal, encompassing entire new industries, including the transistor radio and—eventually—the personal computer. Transistors;invention Electronics

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Braun, Ernest, and Stuart MacDonald. Revolution in Miniature. 2d ed. Cambridge, Mass.: Cambridge University Press, 1982. An excellent account of the development of transistors.
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    xlink:type="simple">Dorf, Richard C., ed. Electrical Engineering Handbook. Boca Raton, Fla.: CRC Press, 1993. A handy technical reference on transistors and related areas.
  • citation-type="booksimple"

    xlink:type="simple">Gregor, Arthur. Bell Laboratories: Inside the World’s Largest Communications Center. New York: Charles Scribner’s Sons, 1972. A popular, illustrated history of Bell Laboratories.
  • citation-type="booksimple"

    xlink:type="simple">Kelly, Mervin J. “The First Five Years of the Transistor.” Bell Telephone Magazine 32 (Summer, 1993): 73-86. Explains the early types of transistor design and their applications.
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    xlink:type="simple">Mabon, Prescott C. Mission Communications: The Story of Bell Laboratories. Murray Hill, N.J.: Bell Telephone Laboratories, 1975. This official history of Bell Labs, written by a corporate official, mixes useful information with a heavy dose of public relations.
  • citation-type="booksimple"

    xlink:type="simple">Marcus, Alan, and Howard Segal. Technology in America: A Brief History. San Diego, Calif.: Harcourt Brace Jovanovich, 1989. A good overview of the history of technology in the United States.
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    xlink:type="simple">Noble, David F. America by Design: Science, Technology, and the Rise of Corporate Capitalism. New York: Alfred A. Knopf, 1977. Analyzes the development of modern technology in the context of corporate capitalism.
  • citation-type="booksimple"

    xlink:type="simple">Orton, John. The Story of Semiconductors. New York: Oxford University Press, 2004. History of the impact of semiconductors upon electronics and human culture. Bibliographic references and index.
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    xlink:type="simple">Riordan, Michael, and Lillian Hoddeson. Crystal Fire: The Invention of the Transistor and the Birth of the Information Age. New York: Norton, 1998. Account of the scientific and industrial developments behind the invention of the transistor and its subsequent applications in computing and other information-based technologies. Bibliographic references and index.

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Categories: History