What is a photovoltaic device?

A photovoltaic device is a device that absorbs light (infrared, visible, and ultraviolet) and produces an electric potential. Photovoltaic devices operate by using the energy from an absorbed photon to excite an electron (or hole) across a p-n junction.

While longer wavelengths (microwaves) and shorter wavelengths (X-rays) of electromagnetic energy can also be used to produce electric potentials, the devices that do this are not considered photovoltaic because they operate on different principles.