Question

In a high quality wafer, where would you expect defect-assisted recombination to be at a maximum?

Answer 1

Solution:

In a high quality wafer, the expectation of defect-assisted recombination to be at a maximum because,

Defect-assisted recombination occurs when an electron falls into a trap, an energy level within the bandgap caused by the presence of a foreign atom or a structural defect. Once the trap is filled it cannot accept another electron. The electron occupying the trap, in a second step, moves into an empty valence band state, thereby completing the recombination process. One can envision this process as a two-step transition of an electron from the conduction band to the valence band or as the annihilation of the electron and hole, which meet each other in the trap.