Semiconductor Electronics Materials Devices And Simple Circuits

Depletion layer contains only fixed positive and negative ions, positive ions on -side and negative ions on -side.

In an extrinsic semiconductor

At high reverse voltage, due to high electric field, the minority charge carriers, while crossing the junction acquire very high velocities. These by collision breaks down the covalent bonds generating more carriers. A chain reaction is established giving rise to high current. This mechanism is called avalanche breakdown

and gates are universal gates. Any digital circuit can be realised by repetitive use of these and gates

Answer (b) The electrons go from the collector region to the base region

NAND

In intrinsic semi-conductor

In a Bipolar Junction Transistor , the current gain is defined as the ratio of change in collector current to change in base current for constant collector voltage in collector-emiitter configuration
i.e.,