at this point will have a small value. Even after the field has passed its maximum value, the electron-hole concentration continues to grow because the secondary carrier generation rate still remains above its average value. For this reason, the electron concentration in the avalanche region attains its maximum value when the field has dropped to its average value. Thus, it is clear that the avalanche region introduces a 90° phase shift between the AC signal and the electron concentration in this region.

With a further increase in t,