How do photovoltaic cells convert sunlight into electrical energy?

Photovoltaic cells convert sunlight into electrical energy through the photovoltaic effect, a process facilitated by the electronic structure of semiconductor materials.12

When sunlight strikes a solar cell, photons transfer their energy to electrons in the semiconductor's absorber layer. This energy excites electrons, allowing them to jump from the lower-energy valence band to the higher-energy conduction band, leaving behind mobile positive charges known as holes.23

In a pure semiconductor, these excited electrons and holes would move randomly and eventually recombine. To generate useful power, solar cells utilize a p-n junction—a contact between two dissimilar semiconductor materials (one p-type and one n-type). This junction creates a built-in electric field that acts as a force, separating the excited electrons and holes and driving them in specific directions. This directed movement creates a direct current that flows through electrical contacts into an external circuit to perform work.1234