Question

The colour of light emitted by a LED depends on

• A. Its reverse bias
• B. The amount of forward current
• C. Its forward bias
• D. Type of semiconductor material

Answer 1

The correct option is D Type of semiconductor material

The color of an LED is a function of the material used to make the junction. There are two main flavors used in visible light LED junctions:

Indium gallium nitride (InGaN) is used to make up the blue, white, true green, and UV types.

Aluminum gallium indium phosphide (AlGaInP or AlInGaP) is used to make the red, yellow, and orange types.

The type of material used also has an effect on the rated forward voltage of the LED.