The collector depletion region also increases under reverse bias, more than does that of the base, because the collector is less heavily doped.
32.
This depletion region is much larger than in a PN diode, and almost constant-size, independent of the reverse bias applied to the diode.
33.
As the bulk silicon is thinned, the photocurrent is increased and reaches a peak as the depletion region of the well to substrate junction is reached.
34.
That said, the whole idea of the crystal diode was that the crystal itself could provide the electrons over a very small distance, the depletion region.
35.
With forward bias, the depletion region is narrow enough that electrons can cross the junction and " inject " into the p-type material.
36.
The depletion region is so named because it is formed from a conducting region by removal of all free charge carriers, leaving none to carry a current.
37.
It is also known as the " space charge region ", although space charge extends a bit further in both directions than the depletion region.
38.
Incident light above the semiconductor's band gap creates photo-induced carriers via electron-hole pair generation in the depletion region of the underlying semiconductor.
39.
As noted above, this photo voltage also forward biases the junction, and so " reduces " the pre-existing field in the depletion region.
40.
Due to heavy concentration of the dopant atom in both nanowire and gate the depletion region is so large that virtually no carriers are present to conduct the current.
