804 



THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1952 



0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 

 WAVELENGTH IN MICRONS 



©LIGHT 

 SOURCE 



V 



RCE 

 BARRIER 



N 



(a) 



>0.2 



5 

 < 3 



(b) 



20 

 10 15 



HI 



a. 



\u 



Q. 10 



2 

 < 



2 



I- 

 z 



(t 



D 



O -10 



-15 



-6 -5 -4 



-3 -2 -1 

 VOLTS 



CC1 



Fig. 2a — Spectral response of internal barrier in silicon. 

 Fig. 2b — Voltage and current photosensitivity of internal barrier in silicon. 

 Fig. 2c — Rectification characteristic of internal barrier, dark and illuminated. 



