In an n-type semiconductor, the donor impurities contribute:
**Semiconductor properties** distinguish from conductors and insulators by temperature dependence and doping response. At 0 K intrinsic acts as insulator, conductivity due to thermally generated electron-hole pairs, number of outer electrons 4 for Si/Ge forming covalent bonds, each atom shares electrons, crystal with N atoms has 4N valence electrons, 2N bonds. Pentavalent donor impurities (e.g., As, P) in an n-type semiconductor donate extra electrons for conduction, significantly increasing the number of free electrons beyond intrinsic levels. Substituting values gives Extra electrons, which
Ref: NCERT > Physics Book > Electronic Devices > Semiconductors, Types and Energy Bands