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- Semiconductor Devices Tutorial
- Semiconductor Devices - Home
- Introduction
- Atomic Combinations
- Conduction in Solid Materials
- Conductivity & Mobility
- Types of Semiconductor
- Doping in Semiconductors
- Junction Diodes
- Depletion Zone
- Barrier Potential
- Junction Biasing
- Leakage Current
- Diode Characteristics
- Light Emitting Diode
- Zener Diode
- Photo Diode
- Photovoltaic Cells
- Varactor Diode
- Bipolar Transistors
- Construction of a Transistor
- Transistor Biasing
- Configuration of Transistors
- Field Effect Transistors
- JFET Biasing
- Semiconductor Devices - MOSFET
- Operational Amplifiers
- Practical Op-Amps
- Semiconductor Devices - Integrator
- Differentiator
- Oscillators
- Feedback & Compensation
- Semiconductor Devices Resources
- Quick Guide
- Semiconductor Devices - Resources
- Semiconductor Devices - Discussion
Semiconductor Devices - Junction Diodes
A crystal structure made of P and N materials is generally known as junction diode. It is generally regarded as a two-terminal device. As shown in the following diagram one terminal is attached to P-type material and the other to N-type material.
The common bond point where these materials are connected is called a junction. A junction diode allows current carriers to flow in one direction and obstruct the flow of current in the reverse direction.
The following figure shows the crystal structure of a junction diode. Take a look at the location of the P type and N type materials with respect to the junction. The structure of crystal is continuous from one end to the other. The junction acts only as a separating point that represents the end of one material and the beginning of the other. Such structure allows electrons to move thoroughly in the entire structure.
![Junction](/semiconductor_devices/images/junction.jpg)
The following diagram shows two portions of semiconductor substance before they are shaped into a P-N junction. As specified, each part of material has majority and minority current carriers.
![Crystal Structure](/semiconductor_devices/images/crystal_structure.jpg)
The quantity of carrier symbols shown in each material indicates the minority or majority function. As we know electrons are the majority carriers in the N type material and holes are the minority carriers. In P type material, holes are the majority carriers and electrons are in the minority.