How do light dependent resistors work with photons and electrons?

[Unredeemed]

How does a light dependent resistor (photoresistor) work in terms of photons and electrons?

Thanks,
Jamie

 

[mgb_phys]

In an intrinsic semiconductor material like silicon, the electrons are held onto the atom strongly enough that the material is normally an insulator.
A photon with enough energy can excite an electron up into the conduction band where it is more free of the atom and can move through the material carrying a current.
The more light, the more free electrosn, the more current and th elower the resistance.

 

[Redbelly98]

mgb_phys has given a good description of the physics behind light dependent resistors. FYI, they are typically made from cadmium sulfide (CdS).