LED Light Sensor

Hello. does anyone know what kind of light the different LEDs react most to? where each LED is stronger than anotehr one.

like if a RED led is better at detecting blue light, and an orange one is best at yellow and green. etc

also, how does it actually work? does anyone have a simple explaination? i have trouble to read something from the LED to give me a number depending on the light.

LEDs typically respond most to the same wavelength they emit, and to shorter wavelengths.

They work rather like the photo-electric effect, absorbing a photon with enough energy to create an
electron-hole pair, which then get swept apart across the electric field at the pn junction. The
energy is called the bandgap and depends on the semiconductor material.

White LEDs are different as they are actually blue LEDs with fluoresecent material in front.


Useful reading here