DIFFUSED p-n JUNCTION SILICON RECTIFIERS 



677 



z 



LU 

 CE 



q: 



D 

 O 



-If 



TIME, t — *- 



Fig. 14 — Recovery effect in silicon rectifiers. 



microseconds. It can be shown that the longer recovery times are associ- 

 ated with higher Hfetimes of minority carriers. More interesting, how- 

 ever, is the fact that these devices will have their excellent rectification 

 characteristics to frequencies near the reciprocal of the recovery time. 

 Measurements have been made of the rectification ability of typical 

 small and medium size units by using the circuit shown in Fig. 15. The 

 results of normalized rectified current versus frequency are given in 

 [Fig. 16 and it is seen that these units could be used to rectify power up 

 to 1 kc/sec without any appreciable loss of efficiency. 

 \ 5.6 It is interesting to note that many of the electrical measurements 

 ,inade with the diffused barrier silicon rectifiers are self-consistent and 

 jean be related to simple concepts of semiconductor theory. As an exam- 

 !ple, experimental measurements indicating variations of recovery time 

 I of units are related to variations in minority carrier lifetime which in 

 turn are related to experimental variations in the forward characteristic 



OSCILLATOR 



AAA- 

 1000 n 



Fig. 15 — Rectification measuring circuit. 



