Semiconductor Theory Flashcards
All atoms consist of what?
Electrons, protons, and neutrons
All matter is composed of _____.
Atoms
except _______, which does not have a neutron.
Normal hydrogen
What is the outermost shell called?
Valence shell
What is the electrons on the shell are called?
Valence electrons
It is the massive center of an atom?
Nucleus
What is the particle inside the proton called?
Quarks
It’s the positively charged particle.
Proton
It’s the negatively charged particle.
Electron
Niels Behr proposed that the electrons in an atom circle the nucleus in different obits, similar to the Way planets orbit the sun in our solar system.
The Bohr Model
The Bohr model is often referred to as the
Planetary model
The nucleus consists of
Positively charged particles and uncharged particles called neutrons
Another view of the atom and considered a more accurate representation, but it is difficult to visualize.
Quantum model
A substance, body or material which has more electrons that are free to move (free electrons).
Conductor
are also conductors of electricity
Electrolytes and ionized gases
is a material that does not conduct electrical current under normal conditions.
Insulator
substance body or material that has a characteristic in between a conductor and insulator.
Semiconductor
with more than four valence electrons but ideally it has 8 valence electrons
Insulator
with four valence electrons
Semiconductor
Elementary Semiconductors
• Silicon (Si)
• Germanium (Ge)
Compound semiconductors
• Gallium Arsenide (GaAs)
• Aluminum Arsenide (AlAs)
• Gallium Phosphide (GaP)
Typical Resistivity Values
CONDUCTOR: COPPER:
p = 10^-6 Ohm-cm
Typical Resistivity Values
Semiconductor
Germanium :
Silicone :
p = 50 Ohm-cm
p = 50k Ohm-cm
Typical Resistivity Values
INSULATOR : Mica :
p = 10^12 Ohm-cm
1 to 3 valence electrons
Conductor
4 valence electrons
Semiconductor
Full valence shell
Insulator
approximately the sum of the number of protons and neutrons of an atom
Atomic mass or weight
the number of protons in the nucleus or the number of electrons in an atom
Atomic number
the highest energy band of an atom which can be filled with electrons
Valence band
energy band in which electrons can move freely
Conduction band
Electrons can jump from one orbit to another by what?
Emitting or absorbing
Mass/charge of electron, proton, and neutron
Electron
9.1096 x10^31
1.6022 x 10^-19
1.6022 x10^11
Proton
1.6726 x10^ -27
+1.6022 ×10^-19
9.5791 x 10^7
Neutron
1.6726 x10^27
0
0
Mass of proton or neutron is ______ times that of electron.
1,836
The energy difference between the conduction band and valence band. It is the energy required to move or transfer a valence electron at the valence band to the conduction band.
Energy gap
the region where the valence shell and valence electrons are occupying. It is the highest energy level before conduction band.
Valence band
the region where free electrons are said to be present. Electrons at this band have a higher energy level than those electrons at the valence band.
Conduction band
the region in an atom where no electrons exist, It is in between two allowed bands, such as between valence and conduction bands.
Forbidden band
whenever a neutral atom losses one or more of its electron/s, it becomes a positively charge atom and is referred to as a ___
Positive ion
if a neutral atom gains electron/s it becomes negatively charge and is called a _________
Negative ion
results from attractive forces between positive and negative ions or between pairs of oppositely charges ions.
lonic bonds or Electrovalent bonds or Electrostatic bonds
attractive forces results from a group of positive ions and electrons which are free to move about among its ions.
Metallic bonds
