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How LED Works and Key Materials Explained

Date：

2025-07-16

That's a great summary of how an LED (Light Emitting Diode)** works! Here's a slightly expanded explanation with key details:

How an LED Works:
1. **Semiconductor Structure** – An LED is made of a compound semiconductor (e.g., GaAs, GaP, or GaAsP) with a p-n junction.
- The p-side(anode) has an excess of holes (positive charge carriers).
- The n-side (cathode) has an excess of electrons (negative charge carriers).

2. Forward Bias Activation

– When a forward voltage is applied:
- Electrons from the **n-region** move toward the **p-region**.
- Holes from the **p-region** move toward the **n-region**.

3Recombination & Light Emission – At the junction, electrons recombine with holes, releasing energy in the form of **photons** (light).
- The color (wavelength) of the emitted light depends on the **bandgap energy** of the semiconductor material.
- Red/Yellow LEDs: Often use **GaAsP (Gallium Arsenide Phosphide)**.
- Blue/White LEDs: Use GaN (Gallium Nitride) or **InGaN (Indium Gallium Nitride)**.

4. Efficiency & Advantages

– LEDs are highly efficient because most energy is converted into light (not heat, unlike incandescent bulbs). They also have a long lifespan and low power consumption.

Key Materials & Colors:**
| Material | Color Emitted** | **Application Example** |
|--------------------|------------------|-------------------------|
| GaAs (Gallium Arsenide) | Infrared (IR) | Remote controls, sensors |
| GaP (Gallium Phosphide) | Red, Green, Yellow | Indicator lights |
| GaAsP (Gallium Arsenide Phosphide) | Red to Yellow | Traffic signals, displays |
| InGaN (Indium Gallium Nitride) | Blue, Green, White | LED screens, lighting |

Would you like more details on any specific aspect, like quantum efficiency, manufacturing, or applications?

LED ,light Emitting Diode