What is led?
A LED (Light Emitting Diode) is a tiny electronic component that produces light when electricity flows through it. Unlike traditional bulbs, it doesn’t have a filament; instead, it uses a semiconductor material that emits photons (light particles) when energized.
Let's break it down
- Semiconductor: The core material (usually gallium arsenide or gallium phosphide) that allows current to flow in one direction.
- PN junction: Two types of semiconductor (positive “P” and negative “N”) are joined together. When voltage is applied, electrons cross the junction and release energy as light.
- Forward bias: The LED lights up only when the positive side of the power source is connected to the P side and the negative to the N side.
- Color: The color of the light depends on the semiconductor’s chemical composition; different materials emit different wavelengths.
Why does it matter?
LEDs are far more energy‑efficient than incandescent or fluorescent lights, turning most of the electricity into light instead of heat. This saves power, reduces electricity bills, and lowers carbon emissions. Their long lifespan (often 25,000+ hours) means fewer replacements and less waste.
Where is it used?
- Household lighting (bulbs, strip lights, flashlights)
- Electronic displays (TV screens, smartphones, computer monitors)
- Indicators on appliances, cars, and industrial equipment
- Automotive lighting (headlights, brake lights, interior lights)
- Medical devices, horticulture grow lights, and signage
Good things about it
- High energy efficiency (up to 80‑90% of power becomes light)
- Very long operational life
- Small size and lightweight
- Instant on/off with no warm‑up time
- Wide range of colors without needing filters
- Durable and resistant to shock and vibration
Not-so-good things
- Higher upfront cost compared to cheap incandescent bulbs
- Light can be directional, requiring diffusers or lenses for even illumination
- Some LEDs contain small amounts of hazardous materials (e.g., lead, arsenic) that need proper recycling
- Color rendering can be less natural than incandescent light for certain applications
- Performance can drop in very cold temperatures unless specially designed.