Semiconductor diode theory

Translated into English as "semiconductor, " the German word "halbleiter" was first used in 1911 to describe materials with electrical conductivities between those of metals (conductors) and insulators. But a good explanation of semiconductor behavior eluded scientists for decades. As late as 1931, physicist Wolfgang Pauli opined that "one shouldn't work on semiconductors, that is a filthy mess; who knows whether any semiconductors exist."

While working at Werner Heisenberg's institute in Leipzig, Germany that year, Cambridge University physicist Alan Wilson adapted the quantum theory of solids being developed there by Felix Bloch and Rudolf Peierls to create a model of semiconductor behavior. In two papers titled "The Theory of Electronic Semi-Conductors, " he proposed that their peculiar properties were due to the presence of impurity atoms in otherwise pure crystals of these materials. In 1932 Wilson also tried to explain the one-way current flow in a point-contact rectifier (1874 Milestone) as due to quantum-mechanical tunneling from metal to semiconductor - or vice-versa. But along with similar attempts from other scientists in the early 1930s, his explanation eventually proved wrong.

Satisfactory explanations of rectification finally emerged in 1938. Boris Davydov at the Ioffe Physico-Technical Institute of the Russian Academy of Sciences, Leningrad, Nevill Mott at Bristol University, England, and Walter Schottky at Siemens and Halske in Munich, Germany independently attributed the phenomenon to a concentration of electrons on the semiconductor surface that set up an asymmetric barrier to current flow. Schottky's name became familiar to a new generation of technologists through the eponymous diode of the 1970s. (1969 Milestone)

• Wilson, A. H. "The Theory of Electronic Semi-Conductors, " Proceedings of the Royal Society of London. Series A, Vol. 133, No. 822 (Oct. 1, 1931) pp. 458-491 and "The Theory of Electronic Semi-Conductors II, " in Vol. 134, No. 823 (Nov. 3, 1931) pp. 277-287
• Wilson, A. H. "A Note on the Theory of Rectification, " Proceedings of the Royal Society of London. Series A, Vol. 136, No. 830 (June 1, 1932) pp. 487-498
• Davydov, B. "On the rectification of current at the boundary between two semiconductors, " Compt. Rend. Doklady Acad. Sci., URSS Vol. 20 (1938) pp. 279-282 also “The rectifying action of semiconductors” Tech Phys USSR Vol. 5 (1938) pp. 87-95
• Mott, N. F. "Note on the contact between a metal and an insulator or semiconductor, " Proceedings of Cambridge Philosophical Society Vol. 34 (1938) pp. 568-572
• Schottky, W. "Halbleitertheorie der Sperrsschicht." Naturwissenschaften Vol. 26 (1938) pp. 843. Abstract in English as "Semiconductor Theory of the Blocking Layer" in Sze, S.M. Semiconductor Devices: Pioneering Papers. (World Scientific Publishing Co., 1991) pp. 381.
• Mott. N. F. "The Theory of Crystal Rectifiers, " Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences Vol. 171, No. 944 (May 1, 1939) pp. 27-38

• Hoddeson, L., Braun, E., Teichmann, J., Weart, S. Out of the Crystal Maze. (Oxford University Press, 1992) p. 121
• Riordan, M & Hoddeson, L. Crystal Fire: The Birth of the Information Age. (New York: W. W. Norton, 1997) p. 66