Question

Which of The following is heavily doped
A. Zener Diode
B. Light Emitting
C. Photodiode
D. Both A and B

Answer 1

Doping is the intentional introduction of impurities into an intrinsic semiconductor to modulate its electrical, optical, and structural properties in semiconductor manufacturing. An extrinsic semiconductor is a material that has been doped.

Complete answer:
A degenerate semiconductor is a semiconductor that has been doped to such high levels that it behaves more like a conductor than a semiconductor. Doping is also known as activation in the context of phosphors and scintillators. In some pigments, doping is also used to control the color.

Option A: Zener diode: A Zener diode is a silicon semiconductor device that allows current to flow both forward and backward. When a certain specified voltage is reached, the diode's special, heavily doped p-n junction is designed to conduct in the opposite direction.

Option B: Light Emitting: Injection luminescence is used in light-emitting diodes (LED lamps), which are commonly found in electronic equipment. The joining of two semiconductor crystals with opposing doping is done. An electric current applied in the correct direction at the junction allows electrons and holes to recombine and emit light.

Option C: Photodiode: Between the P and N layers of this photodiode is an intrinsic semiconductor layer (N-doped or sometimes slightly doped), which reduces the PN junction capacitance and thus increases the maximum switching speed, which is especially useful for fiber optic communication.

Option D: Both A and B: Zener diode and Light Emitting both are heavily doped.

Thus, the correct answer is option D.

Note: As the (usually silicon) boule grows, some dopants are added, giving each wafer an almost uniform initial doping. Select areas - typically controlled by photolithography - are further doped by processes like diffusion and ion implantation to define circuit elements, with the latter method being more popular in large production runs due to increased controllability.