What is a hole? Which doping creates a hole?

What is doping ?

What is Ozone hole? Why does Ozone hole formed over Antartica? How will enhanced UV radiations affect us?

A p-type semiconductor has acceptor energy levels 57 meV(millielectron volt) above the valence band.Find the maximum wavelength of the radiation,which can create a hole?

What is ozone hole? What are the causes of formation of ozone hole?

Hole is