ABSTRACTS OF TECHNICAL ARTICLES 515 



Interpretation of e/m Values for Electrons in Crystals. W. Shockley^ 

 Letter to the Editor. Phys. Rev., 88, p. 953, Nov. 15, 1952. 



Transistor Electronics: Imperfections, Unipolar and Analog Transistors. 

 W. Shockley^ I.R.E., Proc, 40, pp. 1289-1313, Nov., 1952. 



The electronic mechanisms that are of chief interest in transistor electronics 

 are discussed from the point of view of solid-state physics. The important con- 

 cepts of holes, electrons, donors, acceptors, and deathnium (recombination center 

 for holes and electrons) are treated from a unified viewpoint as imperfections in a 

 nearly perfect crystal. The behavior of an excess electron as a negative particle 

 moving with random thermal motion and drifting in an electric field is described 

 in detail. A hole is similar to an electron in all regards save sign of charge. Some 

 fundamental experiments have been performed with transistor techniques and 

 exhibit clearly the behavior of holes and electrons. The interactions of holes, 

 electrons, donors, acceptors, and deathnium give rise to the properties of p-n 

 junctions, p-n junction transistors, and Zener diodes. Point-contact transistors 

 are not understood as well from a fundamental viewpoint. A new class of unipolar 

 transistors is discussed. Of these, the analog transistor is described in terms of 

 analogy to a vacuum tube. 



Unipolar ''Field-Effect" Transistor. W. Shockley^ I.R.E., Proc, 40, 

 pp. 1365-1376, Nov., 1952. 



The theory for a new form of transistor is presented. This transistor is of the 

 "field-effect" type in which the conductivity of a layer of semiconductor is modu- 

 lated by a transverse electric field. 



Since the amplifying action involves currents carried predominantly by one 

 kind of carrier, the name ''unipolar" is proposed to distinguish these transistors 

 from point-contact and junction tj^jes, which are "bipolar" in this sense. 



Regarded as an analog for vacuum-tube triode, the unipolar field-effect traijs- 

 sistor may have a m^ of 10 or more, high output resistance, and a frequency 

 response higher than bipolar transistors of comparable dimensions. 



Control of Frequency Response and Stability of Point-Contact Transistors. 

 B. N. SladeI. I.R.E., Proc, 40, pp. 1382-1384, Nov., 1952. 



The frequency response and stability of point-contact transistors are deter- 

 mined to a large degree by control of the point-contact spacing and germanium 

 resistivity. Stabihty is particularly important in amplifiers in which the im- 

 pedances of the emitter and collector circuits are very small in the frequency 

 range in which the transistor is designed to operate. Satisfactory stability has 

 been obtained with developmental transistors having a frequency cutoff (3-db 

 drop in the current amplification factor, alpha) ranging from 10 to 30 mc. These 

 transistors operate under approximately the same dc bias conditions used with 

 lower-frequency transistors, and have an average power gain of approximately 

 20 db. By means of the methods outlined, transistors which oscillate at frequen- 

 cies as high as 300 mc have been made. 



^ Bell Telephone Laboratories. 



