photovoltaic device
A solar cell is made from a layet of p-type semiconductor surrounding a disk of n-type material. When light strikes the p-n junction between them electrons are released and can flow as an electric current in a circuit.
A photovoltaic device is a solid-state electrical device that converts light directly into direct current electricity of voltage-current characteristics that are a function of the characteristics of the light source and the materials in and design of the device. Solar photovoltaic devices are made of various semiconductor materials including silicon, cadmium sulfide, cadmium telluride, and gallium arsenide, and in single crystalline, multi-crystalline, or amorphous forms.