How the First Infrared LED Was Invented

Texas Instruments' 1962 patent for the first practical semiconductor diode that emits infrared light when electricity passes through it.

What it covers

The device uses a gallium-arsenide crystal body with two distinct layers, a p-type and an n-type, which meet to form a p-n junction. When an electrical current is applied through the contacts, the junction emits infrared light. The patent specifically details a design with a large contact on one side and a specialized, multi-part contact on the other to efficiently manage current flow and light emission. This structure was the foundational blueprint for modern light-emitting diodes.

What it doesn't cover

• —Does not cover visible light LEDs, as this specific design emits infrared radiation.
• —Does not cover LEDs made from materials other than gallium-arsenide.
• —Does not cover light-emitting devices that rely on non-semiconductor materials like filaments or gas discharge.

The clever bit

The inventors realized that gallium-arsenide was far more efficient at converting electrical energy directly into light than the silicon or germanium used in transistors at the time.

Why it matters

This patent marks the birth of the light-emitting diode (LED). It transitioned light production from heat-based methods, like incandescent bulbs, to efficient electron-based emission. It is the ancestor of everything from your TV remote's signal to fiber optic data transmission.

Real-world examples

• 1.Infrared remote controls
• 2.Fiber optic communication systems
• 3.Early optoisolators
• 4.Night vision illumination systems