Photoconductive cells are devices that use a photoconductive material, such as cadmium sulfide, to change their electrical conductivity when exposed to light.
Cadmium sulfide cells are commonly used as light sensors in a variety of applications, including automatic light control systems, photographic light meters, and solar cells.
When exposed to light, the cadmium sulfide material in the cell absorbs photons and generates electron-hole pairs, which increase the conductivity of the material and allow it to conduct an electrical current.
Cadmium sulfide cells have several advantages as light sensors, including a wide spectral response range, good linearity, and a low cost.
However, they also have some limitations, such as temperature sensitivity and susceptibility to degradation over time.