This document defines key terms related to semiconductors and diodes. It explains that semiconductors have conductivity properties between conductors and insulators. Doping adds impurities to semiconductors to increase charge carriers, which are electrons in N-type materials and holes in P-type materials. A diode has an anode and cathode, and conventional current flows from negative to positive terminals. When a diode is forward biased with positive to P-type and negative to N-type, the junction barrier is reduced and current flow is maximum.

1. Alan Bullard

2. Definitions
 Semi-Conductor: is a device that has the resistance of
an insulator and the conduction of a conductor. Most
devices are made up of Silicon or Germanium.
 Doping: the process of adding impurities to the device
to increase the number of free current carriers.
 Current carriers: Majority carriers are the
predominate carriers in the semi-conductor material.
If it is N-Type material (Arsenic) it is electrons and
negative. If it is P-Type material (Aluminum) then it is
holes and positive.

3. Definitions (continued)
 Recombination: excess electronics fall back into their
perspective orbits and limit current flow.

4. Diode Schematic Diagram
 The diode is comprised of
an “Anode-positive” side
and the “Cathode-
negative” side.
 Conventional current flow
is from negative to
positive.
 An easy way to remember
is Cathode sounds like “K”,
which is the shape of the
Cathode.

5. Diode Block Diagram
 The junction barrier (JB) is
where recombination
occurs and very little
current carriers.
 P-Type: doped with
Aluminum producing
excessive holes and is
positive.
 N-Type: doped with
Arsenic producing
excessive electrons and is
negative.

6. Diode Biasing
 Biasing is in reference to
the power supply and the
diode material.
 When you have the
positive terminal
connected to the P-Type
material and the
negative terminal
connected to the N-Type
material it is forward
biases.
+ -

7. Junction Barrier
 This diode is reversed
biased. As can be seen
the junction barrier is
much larger and current
flow has stopped.

8. Junction Barrier
 Here the diode is
Forward biased and as
can be seen the junction
barrier is almost gone.
In this state current flow
is at its maximum.