## How to Calculate and Solve for Mobility of an Ionic Specie | Electrical Properties

The image of mobility of an ionic specie is shown below.

To compute for mobility of an ionic specie, five essential parameters are needed and these parameters are Valence (nI), Electrical Charge (e), Diffusion Coefficient (DI), Boltzmann’s Constant (K) and Temperature (T).

The formula for calculating the mobility of an ionic specie:

μI = nIeDI/KT

Where:

μI = Mobility of an Ionic Specie
nI = Valence
e = Electrical Charge
DI = Diffusion Coefficient
K = Boltzmann’s Constant
T = Temperature

Let’s solve an example;
Find the mobility of an ionic specie when the valence is 18, the electrical charge is 9, the diffusion coefficient is 12, the boltzmann’s constant is 6 and the temperature is 3.

This implies that;

nI = Valence = 18
e = Electrical Charge = 9
DI = Diffusion Coefficient = 12
K = Boltzmann’s Constant = 6
T = Temperature = 3

μI = nIeDI/KT
μI = (18)(9)(12)/(6)(3)
μI = 1944/18
μI = 108

Therefore, the mobility of an ionic specie is 108 m²/(V. s).

## How to Calculate and Solve for Electrical Conductivity for Extrinsic p-type Semiconductor | Electrical Properties

The electrical conductivity for extrinsic p-type semiconductor is illustrated by the image below.

To compute for electrical conductivity for extrinsic p-type semiconductor, three essential parameters are needed and these parameters are Number of Holes (p), Hole Mobility (μh) and Electrical Charge (e).

The formula for calculating electrical conductivity for extrinsic p-type semiconductor:

σ ≅ p|e|μh

Where:

σ = Electrical Conductivity for Extrinsic p-type Semiconductor
p = Number of Holes
μh = Hole Mobility
e = Electrical Charge

Let’s solve an example;
Find the electrical conductivity for extrinsic p-type semiconductor when the number of holes is 24, the hole mobility is 12 and the electrical charge is 4.

This implies that;

p = Number of Holes = 24
μh = Hole Mobility = 12
e = Electrical Charge = 4

σ ≅ p|e|μh
σ ≅ (24)|4|(12)
σ ≅ (24)(4)(12)
σ ≅ 1152

Therefore, the electrical conductivity for extrinsic p-type semiconductor is 1152 S/m.

Calculating the Number of Holes when the Electrical Conductivity for extrinsic p-type semiconductor, the Hole Mobility and the Electrical Charge is Given.

p = σ / μh(e)

Where:

p = Number of Holes
σ = Electrical Conductivity for Extrinsic p-type Semiconductor
μh = Hole Mobility
e = Electrical Charge

Let’s solve an example;
Find the number of holes when the electrical conductivity for extrinsic p-type semiconductor is 42, the hole mobility is 3 and the electrical charge is 1.

This implies that;

σ = Electrical Conductivity for Extrinsic p-type Semiconductor = 42
μh = Hole Mobility = 3
e = Electrical Charge = 1

p = σ / μh(e)
p = 42 / 3(1)
p = 42 / 3
p = 14

Therefore, the number of holes is 14.

## How to Calculate and Solve for Electrical Conductivity for Extrinsic n-type Semiconductor | Electrical Properties

The image of electrical conductivity for extrinsic n-type semiconductor is shown below.

To compute for electrical conductivity for extrinsic n-type semiconductor, three essential parameters are needed and these parameters are Number of Free Conducting Electrons (n), Electron Mobility (μe) and Electrical Charge (e).

The formula for calculating the electrical conductivity for extrinsic n-type semiconductor:

σ ≅ n|e|μe

Where:

σ = Electrical Conductivity for Extrinsic n-type Semiconductor
n = Number of Free Conducting Electrons
μe = Electron Mobility
e = Electrical Charge

Let’s solve an example;
Find the electrical conductivity for extrinsic n-type semiconductor when the number of free conducting electrons is 12, the electron mobility is 6 and the electrical charge is 4.

This implies that;

n = Number of Free Conducting Electrons = 12
μe = Electron Mobility = 6
e = Electrical Charge = 4

σ ≅ n|e|μe
σ ≅ (12)|4|(6)
σ ≅ (12)(4)(6)
σ ≅ 288

Therefore, the electrical conductivity for extrinsic n-type semiconductor is 288 S/m.

Calculating the Number of Free Conducting Electrons when the Electrical Conductivity for Extrinsic n-type Semiconductor, the Electron Mobility and the Electrical Charge is Given.

n = σ / μe(e)

Where:

n = Number of Free Conducting Electrons
σ = Electrical Conductivity for Extrinsic n-type Semiconductor
μe = Electron Mobility
e = Electrical Charge

Let’s solve an example;
Given that, the electrical conductivity for extrinsic n-type semiconductor is 40, the electron mobility is 4 and the electrical charge is 2. Find the number of free conducting electrons?

This implies that;

σ = Electrical Conductivity for Extrinsic n-type Semiconductor = 40
μe = Electron Mobility = 4
e = Electrical Charge = 2

n = σ / μe(e)
n = 40 / 4(2)
n = 40 / 8
n = 5

Therefore, the number of free conducting electrons is 5.

## How to Calculate and Solve for Electrical Conductivity for Intrinsic Semiconductor | Electrical Properties

The image of electrical conductivity for intrinsic semiconductor is shown below.

To compute for electrical conductivity for intrinsic semiconductor, five essential parameters are needed and these parameters are Number of Holes (p), Number of Free Conducting Electrons (n), Hole Mobility (μh), Electron Mobility (μe) and Electrical Charge (e).

The formula for calculating electrical conductivity for intrinsic semiconductor:

σ = n|e|μe + p|e|μh

Where:

σ = Electrical Conductivity for Intrinsic Semiconductor
p = Number of Holes
n = Number of Free Conducting Electrons
μh = Hole Mobility
μe = Electron Mobility
e = Electrical Charge

Let’s solve an example;
Find the electrical conductivity for intrinsic semiconductor when the number of holes is 14, the number of free conducting electrons is 12, the hole mobility is 8, the electron mobility is 4 and the electrical charge is 2.

This implies that;

p = Number of Holes = 14
n = Number of Free Conducting Electrons = 12
μh = Hole Mobility = 8
μe = Electron Mobility = 4
e = Electrical Charge = 2

σ = n|e|μe + p|e|μh
σ = (12)|2|(4) + (14)|2|(8)
σ = (12)(2)(4) + (14)(2)(8)
σ = 96 + 224
σ = 320

Therefore, the electrical conductivity for intrinsic semiconductor is 320 S/m.