diagram for fabrication of pn junction?

Answer 1

dont know

Answer 2

P-material contains a shortage of valence electrons (holes) whereas N material contains an excess of valence electrons.
Applied current, properly biased, causes the electrons to combine with holes, and electrons move through the PN junction with little electrical resistance. Reverse biasing a PN junction moves electrons away from the junction, creating a larger barrier region and high resistance.
P-material is formed by doping semiconductor material with atoms containing 3 valence electrons(Aluminum). N-material is formed by doping with atoms containing 5 valence electrons(arsenic) Pure semiconductor material (Si, Ge) contains 4 valence electrons. The most stable configuration is 8 valence electrons.
From this you can draw your diagram showing a "hole" next to an Aluminum atom when the electrons are shared with Si to create the stable 8 electron configuration, and a excess of electrons when silicon is adjecent to an arsenic atom with 5 valence electrons.