Which of the following photoelectric devices is most suitable for digital applications?

Explanation

A photovoltaic cell is generally called a solar cell. It is a non-mechanical device that converts sunlight directly into electricity, whereas a photodiode is a detector of light signals. Therefore, for digital applications (switching/controlling), a photodiode is used. It is notable that solar light is made up of photons. These photons contain different amounts of energy corresponding to different wavelengths of the solar spectrum. Photovoltaic cells are made of semiconductor ma- terials. When photons strike these cells, they transfer energy to them. A photo-emissive device converts electrical energy into light energy, such as LEDs and other light emitters.