1. The pin diode consists of two narrow, but highly doped, semiconductor regions separated by a thicker, lightly doped material called the intrinsic region.

2. Silicon is used most often for its power-handling capability and because it provides a highly resistive intrinsic region.

3. The pin diode acts as an ordinary diode at frequencies above 100 MHz.

Which of the above statements are correct?

The structure of the PIN diode is

• A PIN diode is heavily doped in P and n-type regions and narrow compared to the intrinsic region because of the high doping order.
• The intrinsic region has less doping so it’s thicker compare to the P and n region.

So statement-1 is correct.

• A PIN diode acts as an ordinary diode at low frequency and it acts as a perfect resistor at high frequency.

So statement 3 is incorrect.

Silicon is used most often semiconductor material due to the following regions:

• High-Power handling capacity
• Greater abundance on earth.
• Less expensive
• Provides high resistivity.

So statement 2 is correct.

Hence, option (1) is the correct answer.