The P region of a diode which is positive
The smallest particle of an element that possesses the characteristics of that element
the amount of energy required to produce full conduction across the PN junction in forward bias
The application of a DC voltage to a diode to make it either conduct or block current
The N region of the diode which is negative
A solid material in which the atom are arranged in a symmetrical pattern
A semiconductor device with a single PN junction that conducts current in only one direction.
The process of imparting impurities to an intrinsic (pure) semiconductive material in order to control its conduction characteristics
The condition in which a diode conducts current
An electron that has aquired enough energy to break away from the valence band of the parent atom
The absence of an electron in the valence band of an atom
Ionization (positive ion, negative ion)
The removal or addition of an electron from or to a nuetral atom so that the resulting atom has a positive or negative charge.
The boundry between two different types of semiconductive materials
The condition in which a diode prevents current. ( action like an open switch)
Silicon, Germanium and carbon
A curve showing the relationship of a diode voltage and current
N-type impurity atom
Pentavalent atoms which have five valence electrons
P-type impurity atom
Trivalent atoms which have three valence electrons
is created by the sharing of valence electrons
When a voltage is applied across the semiconductor the free electrons move towars the the positive end (to the right)and form the current
This occurs as valence electrons move from hole to hole (left to right)creating a movement of holes from right to left
The majority carriers in N-type semiconductors
The minority carriers in N-type semiconductors
The majority carriers in P-type semiconductors
The minority carriers in P-type semiconductors
How a PN junction is formed
when part of a material is doped N-type and part is doped P-type. A depletion region forms by ionization and starts at the junction that is devoid of any majority carriers
The barrier potential for a silicon diode
The barrier potential for a germanium diode
What does the dig. multimeter display when the diode is in reverse bias but working properly?
What does the dig. multimeter display when the diode is working in forward bias?
0.7V or 0.3V
Reverse breakdown voltage for a diode
greater than 50V
What does the dig. multimeter display when the diode is open?
OL in forward and reverse bias
What does the dig. multimeter display when the diode is shorted?
0V in forward and reverse bias
IF= forward current for ideal diode model
IF= Forward current for practical diode model
The ideal diode model
Used for troubleshooting and does not give exact voltage or current. It is represented as a switch. Forward bias =closed switch. Reverse bias= open switch.
The practical diode model
includes barrier potentail which is written as V
= 0.7V. V
is the Voltage that is applied to the circuit
Intro to semiconductors