Semiconductor Ele
Classification of metals, insulator And Semiconductor
Material Devices and
On the basis of Energy Band Theory
ON THE BASIS OF
CONDUCTIVITY SEMICONDUCTOR AND ITS TYPES
(1) For metals: Semiconductors exhibit electrical
ρ ∼ 10-2 – 10-8 Ω m
conductivity between conductors
σ ∼ 102 - 108 S/m and non – Conductors. p n
They have high conduc�vity.
(2) For Semiconductors: INTRINSIC SEMICONDUCTORS
ρ ∼ 10-5 – 106 Ω m (1) Pure Semiconductors are intrinsic P – n junction diode
semiconductors. P – n junction diode is the
σ ∼ 105 – 10-6 S/m
(2) ni= ne = nr, Where, ne = no. of Combination of P – type and
They have intermediate free electrons, nh = no. of holes,
conductivity to metals n – type semiconductor.
ni = intrinsic carrier Concentration P – region has mobile majority
and insulators.
(3) Examples:- Ge, Si
(3) For insulators:
holes and immobile – ve ions.
n – region has mobile majority
ρ ∼ 1011 – 1019 Ω m EXTRINSIC SEMICONDUCTORS
free electrons and immobile
σ ∼ 10-11 – 10-19 S/m (1) Impure or doped semiconductors Positively charged ions.
They have low conduc�vity. are said to be extrinsic
semiconductors POTENTIAL BARRIES
σ = electrical conduc�vity
(2) Impurities are added to improve
ρ = resis�vity Conductivity Potential barrier is the potential
difference developed across
depletion region.
The band which is n – type Semiconductor VB = 0.7 for silicon
= 0.3 for germanium
Classification of metals, insulator And Semiconductor
Material Devices and
On the basis of Energy Band Theory
ON THE BASIS OF
CONDUCTIVITY SEMICONDUCTOR AND ITS TYPES
(1) For metals: Semiconductors exhibit electrical
ρ ∼ 10-2 – 10-8 Ω m
conductivity between conductors
σ ∼ 102 - 108 S/m and non – Conductors. p n
They have high conduc�vity.
(2) For Semiconductors: INTRINSIC SEMICONDUCTORS
ρ ∼ 10-5 – 106 Ω m (1) Pure Semiconductors are intrinsic P – n junction diode
semiconductors. P – n junction diode is the
σ ∼ 105 – 10-6 S/m
(2) ni= ne = nr, Where, ne = no. of Combination of P – type and
They have intermediate free electrons, nh = no. of holes,
conductivity to metals n – type semiconductor.
ni = intrinsic carrier Concentration P – region has mobile majority
and insulators.
(3) Examples:- Ge, Si
(3) For insulators:
holes and immobile – ve ions.
n – region has mobile majority
ρ ∼ 1011 – 1019 Ω m EXTRINSIC SEMICONDUCTORS
free electrons and immobile
σ ∼ 10-11 – 10-19 S/m (1) Impure or doped semiconductors Positively charged ions.
They have low conduc�vity. are said to be extrinsic
semiconductors POTENTIAL BARRIES
σ = electrical conduc�vity
(2) Impurities are added to improve
ρ = resis�vity Conductivity Potential barrier is the potential
difference developed across
depletion region.
The band which is n – type Semiconductor VB = 0.7 for silicon
= 0.3 for germanium
