Avalanche Breakdown of p-n Junction

Avalanche Breakdown of p-n JunctionAvalanche breakdown of p-n junction occurs at lower voltage of electric fields and is the result of impact ionization of semiconductor atoms.At certain values of electric field voltage the energy of non major electricity carriers that moves through p-n-junction and collides with crystal lattice atoms is sufficient for valence bonds between these atoms and their electrons to be broken. As a result of impact ionization, new free electrons and holes appear. They in turn are accelerated by the field and create an ever-increasing number of electricity carriers. Ionization process is repeated. It is characterized by avalanche multiplication of carriers and causes the reverse current to increase significantly through the junction. Avalanche breakdown occurs in devices with a wide electron-hole transitions where passing non-major carriers manage to get enough speed. Breakdown does not cause the semiconductor structure to get destroyed, if there is an external circuit that limits the reverse current.

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Science & Technology

Tags:

• breakdown
• p-n junction
• physics
• semiconductors