How does the solar cell work?
Solar cells are made of semiconductors such as silicon, which is currently the most commonly used. A typical solar cell consists of two layers of semiconductor, one P-type (boron-doped) and the other N-type (phosphorous-doped), sandwiched together to form a “P-N junction”. This P-N interface induces an electric field across the junction. When light strikes the cell, energy is transferred to the semiconductor material which knocks electrons loose, allowing them to flow freely. The electric field forces the electrons freed by light absorption to flow in a certain direction. This flow of electrons is a current, and by placing metal contacts on the top and bottom of the cell, current can be drawn to use externally. This current, together with the cell’s voltage (which is a result of its built-in electric field or fields), defines the power (or wattage) that the solar cell can produce. The current (and power) output of a cell depends on its efficiency and size (surface area), and is proport
