Doping

Question 1

How can we manipulate the concentrations of electrons and holes?

Answer 1

Doping

Question 2

What is Doping?

Answer 2

Atoms of other elements replace Si atoms in the crystal lattice

Question 3

Most typical elements for Si Doping?

Answer 3

Boron (B) - 5 Atomic numbers
Phosphorus (P) - 15 Atomic numbers

Question 4

Boron

Answer 4

Is an Acceptor because of his 3 valence electrons (NA)

Question 5

Phosphorous

Answer 5

Is an Donor because of its 5 valence electron (ND)

Question 6

How the concentrations of charge carriers inside a semiconductor are derived?

Answer 6

Assuming the semiconductor is under thermal equilibrium

Question 7

What is the Thermal Equilibrium on a semiconductor?

Answer 7

Is used to describe the unperturbed state of a system, to which no external voltage, magnetic field, illumination, mechanical stress, or other
perturbing forces are applied. In the equilibrium state, the observable parameters of a semiconductor do not change with time.

Question 8

What is the Fermi Level?

Answer 8

The electrochemical potential of the electrons in a material and in this way
it represents the averaged energy of electrons in the material.

Question 9

Amount of Thermal energy level

Answer 9

KBT at 300 K =26.85°C 0.0258 eV

Question 10

Relation in a Intrinsic Semiconductor in equilibrium

Answer 10

n = p = ni

Question 11

n X p in an Intrinsic Semiconductor

Answer 11

ni*2

Question 12

The two basic transport mechanisms in a semiconductor

Answer 12

Drift and Diffusion

Question 13

Define Mobility

Answer 13

Measure of how easily the charge particles can move through a semiconductor material

Question 14

Drift

Answer 14

Charged particle motion in response to an electric field. In an electric field the force acts on the charged particles in a semiconductor, which accelerates the positively
charged holes in the direction of the electric field and the negatively charged electrons in the opposite direction.

Question 15

Diffusion

Answer 15

Process whereby particles tend to spread out from regions of high particle
concentration into regions of low particle concentration as a result of random thermal motion.

Question 16

What is the driving force for the Diffusion Motion?

Answer 16

Gradient in the particle concentration. In contrast to the drift transport mechanism, the particles need not be charged to be involved in the diffusion process. Currents resulting from diffusion are proportional to the gradient in particle concentration.