It is the branch of physics that deals with the emission and effects of electrons and the operation of
Semiconductors The majority carriers move against the
direction of conventional current.
It is a substance, usually a solid chemical
element or compound, that can conduct p-type Semi-Conductor
electricity under some conditions but not
others, making it a good medium for the It is an extrinsic semi-conductor which is
control of electrical current. obtained by doping the impurity atoms of
III group of the periodic table to the pure
A pure semiconductor is called intrinsic Ge and Si semi-conductor.
semiconductor. It has equal numbers of The impurity atoms added, create vaccines
negative carriers (electrons) and positive of electrons (i.e. holes) in the structure and
carriers (holes). are called acceptor atoms.
The majority carriers are holes which
An impure semiconductor is called extrinsic
move in the valence band.
semiconductor. There are two types of
The majority carriers move in the direction
of conventional current
It is an arrangement consisting a p-type
semiconductor brought into a close contact
It is an extrinsic semi-conductor which is with n-type semiconductor.
obtained by doping the impurity atoms of
The Noble prize in physics 2014 was awarded
Vth group of the periodic table to the pure
jointly to Isamu Akasaki, Hiroshi Amano and
Ge and Si semi-conductor.
Shiji Nakamura, for inventing a new energy
The impurity atoms added, provide extra
efficient and environment friendly light
electrons in the structure and are called
sourcethe blue Light Emitting Diode (LED).
The majority carriers are electrons that
move in the conduction band.
PN diode (a) functional diagram, and (b) schematic diagram