A solar panel, also known as a photovoltaic (PV) panel, is a device that converts sunlight into electrical energy through a process called the photovoltaic effect. Solar panels are typically composed of several layers of materials, each with specific functions to facilitate the generation of electricity from sunlight.

1. Top Protective Layer: The top layer of a solar panel is usually made of a durable and transparent material such as tempered glass. This layer serves to protect the internal components from environmental factors like weather, moisture, and debris while allowing sunlight to pass through.
2. Antireflection Coating: Some solar panels have an antireflection coating applied to the top glass layer. This coating helps minimize light reflection and increases the amount of sunlight that can be absorbed by the solar cells.
3. EVA (Ethylene Vinyl Acetate) Encapsulation Layer: Beneath the glass layer, there is a layer of EVA encapsulant that adheres to both the glass and the solar cells. EVA acts as an adhesive and protects the cells from external moisture and physical damage.
4. Solar Cells: The heart of a solar panel is the solar cells, also known as photovoltaic cells. These cells are typically made from semiconductor materials like crystalline silicon or thin-film materials. When sunlight strikes these cells, it excites electrons, generating an electric current.
5. Busbars: Metal ribbons or thin strips called busbars are used to collect the electrical current generated by the solar cells. They are typically made of silver or copper and are strategically placed on the surface of the cells to minimize shading and maximize current collection.
6. Backsheet: The backsheet is another protective layer on the backside of the solar panel. It is usually made of a polymer material and provides further protection against moisture and mechanical stress. It also acts as an electrical insulator.
7. Frame: Many solar panels have an aluminum frame around the edges. This frame provides structural support, rigidity, and protection to the panel. It also facilitates the installation of the solar panel on various surfaces.
8. Junction Box: At the back of the panel, you’ll find a junction box. This box contains diodes and wiring connections. Diodes prevent reverse current flow and protect the panel from damage due to shading or other issues. The junction box also allows for the connection of multiple panels in an array and provides an electrical interface for connecting the panel to an external system.
9. Connector Cables: The junction box is connected to the solar panel via cables. These cables carry the generated electricity from the panel to an inverter or charge controller, which then converts the electricity into a usable form for homes or other applications.
10. Frame Sealing: To ensure the longevity of the solar panel, the edges of the frame and junction box are sealed to prevent moisture ingress.

The combination of these components within a solar panel enables the efficient conversion of sunlight into electricity, making solar panels a valuable source of renewable energy. The electrical output from multiple solar panels can be combined in solar arrays to meet the energy needs of homes, businesses, and other applications.