The PN junction diode conducts only in one direction. So it is known as unidirectional current device. Before going to understand the energy level diagrams, please read construction and biasing of diode.
Read MoreComparative Analysis of Energy Level DiagramsThe pure crystal of semiconductor (Si or Ge) is known as intrinsic semiconductor at room temperature. The Silicon atom has 14 electrons revolving around its nucleus. In first orbit it contains 2 electrons, in second orbit 8 electrons i.e. 4 electrons in last orbit, known as valence electrons.
Read MoreWhat is Intrinsic Semiconductor?Some substances like Germanium, Silicon, Carbon, etc. are neither good conductors like copper nor insulators like glass. The resistivity of these materials lies in between conductors and insulators. Such substances are known as semiconductors.
Read MoreWhat is Conductor, insulator & semiconductor?