HOLE INJECTION IN GERMANIUM 



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1'^ ©+0"_W © ©"©_©_© ©_©"©_®"®'^® 



(a) 



if+ib 

 f ih 



a ylt 



1+) = DONOR 

 + = HOLE 

 - = EXCESS ELECTRON 



~-~-n„= Nh-N, = DENSITY OF DONORS 

 ° ° MINUS ACCEPTORS 



«ro=qb//pno 



" — ff^ q//pP + qbApn = q//p(p+b(no + p)) 



= ^°^'^^'^F'?ro) 1(c) 



'-In=CURRENT CARRIED BY HOLES = (I^ + I b) 



r 



(d) 



f X, DISTANCE THROUGH SEMICONDUCTOR^ *■ 



Fig. 3— Method of measuring hole densities and hole currents. 



(a) Distribution of holes, electrons and donors. Acceptors, which may be present, are 

 omitted for simplicity, the excess of donor density Na over acceptor density .Vo being «o . 



(b) To the right of the emitter the added hole density p is compensated by an equal 

 increase in electron concentration. 



(c) The conductivity is the sum of hole and electron conductivities. 



(d) The total current h + /« to the right of the emitter is carried by /p and /„ in the 

 ratio of the hole to the electron conductivity. 



