826 THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1954 



transient fields are high in this region, essentially because of the inverse 

 square law, the principal contribution to D{t) comes from this region. 

 These two factors — relatively slow dielectric relaxation near the center 

 and principal contribution to D(t) from near the center — combine to 

 give a D{t) characteristic which holds up well until the pulse of injected 

 holes reaches the inner region. This may result in a favorable convex 

 upwards D(t) characteristic. 



ACKNOWLEDGEMENTS 



The writer is indebted to a number of his colleagues for helpful dis- 

 cussions and to W. van Roosbroeck for the calculations for Fig. 4.4, and 

 to R. C Prim for Fig. 4.5. 



REFERENCES 



1.1. W. Shockley and W. P. Mason, J. of Appl. Phys., 25, No. 5, p. 677, 1954^ 

 3.1. W. Shockley, Electrons and Holes in Semiconductors, D. van Nostrand, N. Y., 



1950, p. 312. 

 3 2 ScG RsfGrGHCG 3.1. 



3^3'. W. Shockley, B.'s. T. J., 28, p. 435, 1949, Section 2.4. 

 3.4. See References 3.1 or 3.3. 



4.1. W. Shockley and R. C. Prim, Phys. Rev., 90, pp. 753-758, 1953. See also G. C. 



Dacey, Phys. Rev., 90, pp. 759-763, 1953, and W. Shockley, Proc. I.R.E., 

 40, pp. 1289-1314, 1952. 



4.2. W. Shockley and R. C. Prim, Reference 4.1. 



4.3. E. J. Ryder, Phys. Rev., 90, pp. 766-769, 1953, references. 



4.4. See Shockley and Prim, Reference 4.1. 



5.1. This theory of mobility in higher fields has been published by H. Kromer, 



Zeits f. Physik 134, pp. 435-450, 1953. Kromer considers the theory in con- 

 nection with the values of a in point contact transistors but does not ex- 

 plore it as a power source. The present writer derived the same result in a 

 more primitive form in 1948 as a potential means of obtaining high fre- 

 quency power. However, experimental results by E. J. Ryder did not show 

 evidence of this effect. The effect may possibly have occurred without being 

 recognized because of the absence of an adequate appreciation of the im- 

 portance of the boundary conditions discussed in this section. 



5.2. See Reference 4.3. 



5.3. G. C. Dacey, Phys. Rev., 90, pp. 759-763, 1953. 



5.4. W. Shockley, B. S. T. J., 30, pp. 990-1043, 1951. 



5.5. Personal communication. 



