Double-injection diode as a pulse width modulation element

Double-injection switching devices consist of a p
⁺
and an n
⁺
junction for injecting holes and electrons into the high resistivity semiconductor substrate containing compensated (charged) deep traps. These devices show an S-type switching beyond a certain threshold voltage. One possible use of such DI devices is for pulse width modulation. When the device is pulsed with a voltage V
p
exceeding V
Th
the current output of the device appears with increasing pulse width as V
p
is increased, for a given input pulse width. An inverse relationship between V
p
and the delay with which the pulse appears, has been found experimentally and is being modeled.