formation of pn junction

what is the meaning of formation of pn-junction?

A pn junction is where p-type and an n-type semiconductor material meet or join. P-Type material stands for positive doped semiconductor material and N-Type is negative doped. Diodes, Transistors, and many other semiconductor devices rely on pn junctions. Here is a picture of a pn junction.

"image source":http://bedtimestory-ijamdbest.blogspot.com/2008/09/bipolar-junction-transistor-bjt-is-type.html

Perhaps you're asking about the "forming" process in point-contact diodes? A large brief direct current must be applied to the junction before the diode starts operating properly. It's also an important concept for making your own transistor. Jeri Ellsworth mentions this here below (first time I'd heard of it myself.)

Also note she mentions elsewhere that only phosphor-bronze metal makes a good diode junction with Germanium.


http://www.youtube.com/watch?v=vmotkjMSKnI&feature=player_detailpage#t=230s

On this video go to 3:50, also 5:09