A solar cell captures the energy of light through the photovoltaic effect, where photons excite electrons, creating an electric current.
A solar cell is a device that directly converts the energy of light into electrical energy through a process called the photovoltaic effect. Here's a breakdown:
Energy of Light: Solar cells don't just convert any light, they specifically work with the electromagnetic radiation portion of the light spectrum. This includes visible light, but also invisible forms like ultraviolet and infrared rays.
Photovoltaic Effect: When photons (packets of light) strike the cell's semiconductor material, they knock electrons loose from their atoms. These free electrons can then flow through the cell, generating an electric current.
Here's an analogy to help visualize the process: Imagine a tiny seesaw with a ball on each end. One end represents the bound electrons, and the other represents the excited electrons. When a photon hits the "bound" side, it gives the ball enough energy to jump over to the "excited" side. This imbalance creates a flow of balls (electrons) across the seesaw, generating a current.
Here are some additional details that might be helpful:
Semiconductor material: Silicon is the most common material used in solar cells, but other materials like gallium arsenide and cadmium telluride are also used.
Cell structure: A typical solar cell is made up of layers of n-type and p-type semiconductors, along with electrodes and anti-reflective coatings.
Efficiency: The efficiency of a solar cell refers to the percentage of light energy it can convert into electrical energy. Modern commercial solar cells typically have efficiencies between 15% and 22%.