LED Basics

• LED Basics
• Design for LED
• History
• Sustainability
• FAQs

• Making White Light with Blue LEDs • LED Binning • Lab and Field Measurements • Absolute And Relative  Photometry • LED Thermal  Management • Lighting Terminology • LM79 & LM80 Information Brief • Cutoff Classifications and TM15-07

An LED is a solid-state lighting component that does not utilize electrical filaments or gas. LED lighting is a paradigm shift in the outdoor lighting industry. The effect is a cool, energy-efficient and reliable light source that provides at least 70,000 hours of illumination without the need for lamp maintenance.

How Light is Created

When sufficient voltage is applied to the semi-conductor chip, current flows and the electrons cross the junction from the “N” region to the “P” region (see diagram). The attraction of the electrons in the “N” region to those in the “P” region causes the electrons to combine. When the electrons combine, electromagnetic energy is released as a photon. The material of the chip and the amount of voltage applied determines the wavelength of this energy.

The term “solid-state” refers to the fact that the light in an LED is emitted from a solid object— a semiconductor— rather than from a vacuum or gas tube, as is the case with HID lamps. Unlike traditional lighting, SSL creates visible light with reduced heat generation or parasitic energy dissipation. In addition, its solid-state nature provides for greater resistance to shock, vibration, and wear increasing its lifespan significantly.