Semiconductor Devices and Logic Gates

Phosphorous is a pentavalent impurity.

So, resulting semiconductor is a $n$-type semiconductor. The energy band diagram of a $n$-type semiconductor is shown below

So, the energy levels of impurity atom created in the semiconductor are close to the bottom of the conduction band.

The output of full wave rectifier with capacitor filter for the given AC input is given as

The given logic circuit is

∴ Boolean expression of the given logic circuit is given as

$ Y=\bar{A}+B $