Photovoltaics, also known as solar cells, are devices that convert sunlight into electricity.

They are a clean and renewable source of energy that can be used in a variety of applications, from powering homes and businesses to charging devices on the go.

The basic principle behind photovoltaics is the photovoltaic effect, which occurs when light hits certain materials and causes them to generate an electric current.

This effect was first observed in the 19th century, but it was not until the mid-20th century that scientists began to develop practical photovoltaic devices.

Today, photovoltaics are made using a variety of materials, including silicon, copper indium gallium selenide (CIGS), and cadmium telluride (CdTe).