A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts light energy directly into electrical energy through the photovoltaic effect. It is a photoelectric tube whose electrical properties (such as current, voltage, or resistance) change when it is exposed to light. A single solar cell device is usually the electrical building block of a photovoltaic module, commonly known as a "solar panel". Almost all commercial photovoltaic cells are composed of crystalline silicon, with a market share of 95%. Cadmium telluride thin-film solar cells account for the remainder. Common single-junction silicon solar cells can produce a maximum open-circuit voltage of about 0.5 to 0.6 volts.

Photovoltaic cells can operate under sunlight or artificial light. In addition to generating energy, they can also be used as photodetectors (such as infrared detectors), detect light or other electromagnetic radiation in the visible range, or measure light intensity.

The operation of photovoltaic cells requires three basic properties:

Absorption of light, the generation of excitons (bound electron-hole pairs), unbound electron-hole pairs (via excitons), or plasmas.

Separation of opposite type charge carriers.

Extraction of these carriers individually to an external circuit.

In contrast, solar thermal collectors provide heat by absorbing sunlight, with the purpose of either direct heating or indirect use of heat to generate electricity. On the other hand, a "photoelectrolytic cell" (photoelectrochemical cell) refers to a photovoltaic cell (such as the one developed by Edmond Becquerel and modern dye-sensitized solar cells), or to a device that directly splits water into hydrogen and oxygen using only sunlight.

Photovoltaic cells and solar thermal collectors are two ways to produce solar energy.