A solar cell is the fundamental semiconductor device that converts photons from sunlight into electrical current through the photovoltaic effect. Individual solar cells are the microscopic building blocks that make up larger solar panels, with each cell typically producing 0.5-0.6 volts of direct current (DC) electricity. Solar cells are usually made from silicon, which represents over 95% of the commercial solar cell market.
Physical Structure and Operation
A standard solar cell measures approximately 6 inches by 6 inches and consists of two silicon layers with opposite electrical charges (p-type and n-type). When photons strike the cell, they knock electrons loose from atoms, creating electron-hole pairs that are separated by the cell’s electric field. This movement generates direct current that flows through an external circuit. Efficiency ratings for single cells range from 15-23% depending on material and manufacturing quality.
Types and Applications
Monocrystalline cells offer the highest efficiency (18-23%), while polycrystalline cells provide cost advantages at 15-18% efficiency. Multiple cells (typically 60-72) are soldered together in series and laminated to create a solar panel. Each cell contributes equally to overall panel output, making individual cell quality critical for panel performance.