Changes

Different types of semiconductor have slightly different properties and lend themselves to different applications in various forms of semiconductor devices.

Different types of semiconductor have slightly different properties and lend themselves to different applications in various forms of semiconductor devices.

[[File:Semiconductor.png|center|thumb|508x508px]]

[[File:Semiconductor.png|center|thumb|508x508px|Example of semiconductor]]

=== The Silicon atom ===

=== The Silicon atom ===

The silicon atom has fourteen electrons arranged in such a way that the outer four can be given to, accepted from, or shared with another atom. These 4 outer electrons are called valence electrons, they have the highest energy state.  

The silicon atom has fourteen electrons arranged in such a way that the outer four can be given to, accepted from, or shared with another atom. These 4 outer electrons are called valence electrons, they have the highest energy state.  

[[File:Silicon atom.png|center|thumb|421x421px]]

[[File:Silicon atom.png|center|thumb|421x421px|Silicon atom structure]]

Since no free charge carriers can rest in a position where there is a potential barrier, the regions on either sides of the junction now become completely depleted of any more free carriers in comparison to the N and P type materials further away from the junction. This zone around the '''PN Junction''' is now called the '''Depletion''' Layer.

Since no free charge carriers can rest in a position where there is a potential barrier, the regions on either sides of the junction now become completely depleted of any more free carriers in comparison to the N and P type materials further away from the junction. This zone around the '''PN Junction''' is now called the '''Depletion''' Layer.