Highest yields – and how you reap
added benefits

Now, let‘s say you‘re starting your car on a cold winter morning. As long as the motor is still cold it clearly puts out less power. However, the output increases noticeably as soon as the engine has warmed up. The same applies in what is called the “light soaking effect”.

The light soaking effect is the ability of the module to generate several percent more output as soon as modules are exposed to solar irradiation, than it did at the moment of its production, which was fixed with flash list values (the electrical characteristics of the PV module under standard test conditions).

Light Soaking Effect – only available in this
form in Solar Frontier’s CIS technology

The CIS layer applied to the substrate in several work steps is topped by a nanometer-thick buffer layer. This buffer layer initially forms an energy barrier which hampers the electron flow. Triggered by the photons of the sunlight, the first electrons begin moving and neutralize the initially still existent defective areas in the border of the layers. This makes the energy barrier smaller, facilitates the flow of the next electrons and reduces the series resistance. As a result, the energy flux at the module and the module efficiency are increased.

Unlike conventional CIS, the special technology from Solar Frontier replaces toxic cadmium with zinc (ZnS, ZnQ). Not only is this more environmentally friendly, it also gives rise to the light soaking effect. This effect improves the properties of the buffer layer and module performance is enhanced. This effect is the result of years of intensive work by our Research and Development department.

The effect starts - and stays

The Light Soaking Effect starts after the module’s exposure to sunlight and stabilizes after about 50 hours of sunshine. If the efficiency of a CIS PowerModule increases to a higher value due to the light soaking effect, it will remain stable for the entire life cycle. Output losses occurring over the lifetime of the modules correspond to the natural degradation of less than 0.5% per year.