1270 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1956 

 5 



o 

 f< 0.5 



0.2 



O.I 



0.05 



'! 



0.01 



0.1 



1.0 

 20 



10 



100 



Fig. 7 — Variation of (L — Xo)/( with Zo . 



I/Eo is equal to the value of s on the cubic at x = L. For positive values 

 of A the maximum value of E^/I is L/I = l/\/2£ as can be seen from 

 the cubic. In germanium at room temperature <£ is about 10~ (for 

 2Li = unit length) so the reverse bias produces an additional voltage 

 drop in the junction region equal to about IkT/q. For negative values 

 of A the additional voltage drop near the junction would be higher. 



Comparing (5.3) and (5.13) we see that the junction solution reduces 

 to the zero bias solution when £"" is large compared to Eo" + 2. In this 

 case both solutions have the simple form 



(5.20) 



and 



Vi- V 



Q E 



(5.21) 



Case of Eo Small Compared to I 



Now from (5.7) and (5.8) with xo = L = I\/2£, we have 



£' 



2Fj + {E- Eof (^ + ^' 



(5.22) 



