Electroluminescence is an imaging measurement process that allows you to peer directly into the cells of a solar module and locate potential defects that could have a negative impact on power as well as a module’s lifespan.
The measurement process
External voltage is applied to the module via its connections. Applying the voltage results in recombination of electrons in the cells, which in turn produces a release of photons, and the module glows in the near infrared range, which is invisible to the human eye. The released photon irradiation is then captured by an electroluminescence camera.
General rule: the more photons a cell area releases, the more active this area will be when the cell is producing electricity.
Defects and their documentation
Factors that can in many cases negatively effect module power and lifespan, but are invisible to the human eye:
- Microfissures and chips, as well as complete breakage in one or over several cells
- Cell impurities
- Wafer crystallization defects
- Interrupted contact fingers and/or cell breaks that result in an electric separation, and therefore deactivate individual cell pieces
- Depiction of a sintering belt
- General signs of defective cell processing
The issues and defects presented above can be detected with electroluminescence imaging in just a few minutes, and allow one to draw conclusions about the tested module’s material and processing quality.
Who can take advantage of this offer?
- Above all, this electroluminescence imaging service is aimed at vendors and installers that want to be sure of the quality of incoming goods.
- Moreover, this service is naturally aimed at system operators that want to check the quality of their modules before installation, whether out of general interest or some suspicion of a concrete. Electroluminescence imaging also provides information about a solar module’s aging behavior.
- Insurance companies could find the service useful when determining the direct extent of damage to an insured system, which is often difficult to estimate.
- This service is always at the disposal of research institutes and manufacturers.