A solar cell, also known as a photovoltaic cell, is an electrical device that helps in converting the light energy into electricity by using the photovoltaic effect, which is again, a physical and chemical phenomenon. It is a device (a form of photoelectric cell) whose electrical characteristics like voltage, current, resistance etc vary with exposure to light.
Solar panels or photovoltaic modules are made up of solar cells. Irrespective of the source light (whether it is sunlight or man-made artificial light), solar cells are photovoltaic in nature.
Edmond Becquerel built the world’s first photovoltaic cell in 1839. However, in 1954, Calvin Souther Fuller and Gerald Pearson were the inventors who demonstrated the first practical photovoltaic cell.
OPERATION OF A SOLAR CELL
It requires three basic attributes:
- Absorption of light. It should generate either excitons or electron-hole pairs.
- There should be separation of the charge carriers of the opposite type.
- There should be separate extraction of those charge carriers to the external circuit.
WORKING OF A SOLAR CELL
Solar cells are made up of a semiconductor material like silicon. The light strikes the PV or photo voltaic cell as we know it, and a certain portion of the light gets absorbed. The light energy in the form of photons free the electrons from the atoms, making them flow freely, and forming a current. The metal contacts on the top and bottom half of the PV cell draws up that current to be used as power.
REASONS FOR USING SOLAR CELLS
- They are long lasting sources of energy
- They have low maintenance
- They are a cost-effective source of power supply
- They are non-polluting in nature and are silent in application
- They are convenient to be used and are also flexible source of small amount of power
- They are renewable in nature and would never deplete or go out of resources since sunlight is prominent and ever-lasting.
- They are a source of sustainable power which helps in reducing global warming.
APPLICATIONS OF SOLAR CELL
- Used as a photodetector.
- Used to detect light or electromagnetic radiation in the visible light range.
- Helps in measuring light intensity.
- Used in toys, watches and also calculators.
- Electric fences
- Used for water pumping
- Used as a source of emergency power supply
- They are also used in satellites
- Also used in remote lighting systems