A photoactive layer is used in solar cells for absorbing light. It can be found in all solar cells, but with different panels the photoactive layer is made of different materials. Inorganic layers are made from inorganic materials such as silicon

Silicon

Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...

. The film has a layer arrangement of electrodes and counter electrode with organic layers in between the two. The layer is found underneath the glass, adhesive, and reflection coating, but is the first required part of the cell.

Definition

Photoactive means it can have a chemical reaction

Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...

 with sunlight and/or ultraviolet

Ultraviolet

Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 light. Most of the solar cell is photoactive, but the base of the solar cell only conducts electricity after it has been converted. It can also mean that it responds to photons photoelectrically. This can also relate to a physical reaction, but this does not occur within photoactive layers.

Efficiency

Layers that are thicker are sometimes preferred because they can absorb more light. While sometimes thinner ones are preferred for greater efficiency. The light must pass through the band gap

Band gap

In solid state physics, a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference between the top of the valence band and the...

. For this to work the light must have a minimum energy depending on the cell to pass through. Different cells have a different minimum while the light below the minimum passes through the absorber.

See also

• Photovoltaic module
  Photovoltaic module
  A solar panel is a packaged, connected assembly of solar cells, also known as photovoltaic cells...
  
  
• Solar Cell
  Solar cell
  A solar cell is a solid state electrical device that converts the energy of light directly into electricity by the photovoltaic effect....
  
  
• Amorphous silicon
  Amorphous silicon
  Amorphous silicon is the non-crystalline allotropic form of silicon. It can be deposited in thin films at low temperatures onto a variety of substrates, offering some unique capabilities for a variety of electronics.-Description:...
  
  
• Green technology
• Solar shingles
  Solar shingles
  Solar shingles, also called photovoltaic shingles, are solar cells designed to look like conventional asphalt shingles. There are several varieties of solar shingles, including shingle-sized solid panels that take the place of a number of conventional shingles in a strip, semi-rigid designs...
  
  
• Timeline of solar energy