1250 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1956 



--Ec 



Fig. 1 — Schematic of the field distribution and the three overlapping solutions. 



bination of Jp and J„ Avhich has the same form as / m (2.6) and in 

 which the diffusion term is neghgible except near the junction. As we 

 show in section VI, the effect of unequal mobiHties is (1) to introduce 

 some asymmetry into the curve in the region where the curvature is 

 upward and (2) to displace the curve toward the NI junction (for the 

 case where the electrons have the higher mobility). Thus the field is 

 higher on the side where the carrier mobility is lower, as would be ex- 

 pected. 



III. THE NO-RECOMBINATION CASE 



This section deals with the case where recombination can be neglected 

 in comparison with generation. This will be so where 7ip is small com- 

 pared to Hi . 



The continuity equation for J now becomes 



dJ „ ni 

 — = 2g = — 



ax T 



(3.1) 



( 



