What are Photovoltaic Cells Made Out Of
Photovoltaic cells, also known as solar cells, are devices that convert sunlight directly into electricity. They are made from materials that are capable of absorbing photons, the basic unit of light, and releasing electrons. These materials are carefully selected and engineered to maximize efficiency and durability. Let’s take a closer look at what photovoltaic cells are made out of.
Silicon
Silicon is the most common material used in photovoltaic cells. It is a semiconductor that can easily absorb photons and release electrons when exposed to sunlight. Silicon solar cells can be either monocrystalline, polycrystalline, or amorphous, depending on the type of silicon used and the manufacturing process. Each type has its own advantages and disadvantages in terms of efficiency, cost, and longevity.
Thin-Film Materials
In addition to silicon, photovoltaic cells can also be made from thin-film materials such as cadmium telluride (CdTe), copper indium gallium selenide (CIGS), and amorphous silicon. These materials are deposited in thin layers onto a substrate, which can be flexible or rigid. Thin-film solar cells are lighter and more flexible than traditional silicon cells, making them suitable for applications where weight and shape are important factors.
Perovskite
Perovskite is a relatively new material that has shown significant potential for use in photovoltaic cells. It is a crystalline structure that can be made from a variety of elements, allowing for flexibility in engineering the material for specific performance characteristics. Perovskite solar cells have shown rapid efficiency improvements and are being actively researched for commercialization.
Doping
In addition to the primary materials used in photovoltaic cells, they are also doped with other elements to enhance their performance. For example, adding small amounts of phosphorus or boron to silicon can create regions with an excess or deficiency of electrons, leading to the formation of an electric field that facilitates the separation of electrons and holes, and thus the generation of electricity.
Encapsulation
Photovoltaic cells are typically encapsulated in a protective layer to shield them from environmental factors such as moisture, dust, and UV radiation. The encapsulation materials are chosen for their durability and transparency to sunlight. Common encapsulation materials include glass, polymers, and coatings.
Backsheet
On the backside of a photovoltaic cell, there is often a backsheet material that provides additional protection and electrical insulation. This layer is typically made from a polymer material such as polyvinyl fluoride (PVF) or ethylene tetrafluoroethylene (ETFE).
Conclusion
Photovoltaic cells are made from a variety of materials, each carefully chosen and engineered to enable the efficient conversion of sunlight into electricity. As research and development in the field of solar energy continue to advance, new materials and manufacturing processes will likely lead to further improvements in the performance and affordability of photovoltaic cells.