The Ironman for photovoltaic modules takes place every day in our own quality control laboratory. After all: We only offer the very best IBC SOLAR modules! In order to receive this distinction, the modules must pass a series of endurance tests. In the first article of the series, we will present the electroluminescence procedure.
Pictures that are taken with an electroluminescent camera (EL camera) show the smallest damage to solar cells that is not visible to the naked eye. We use this method, for example, to inspect incoming goods deliveries and can therefore ensure that we only provide our customers with first class modules.
To carry out the electroluminescence picture test in the quality control laboratory we use the natural phenomenon of electroluminescence. This means stimulating a solid object to emit electromagnetic radiation by applying an electric voltage. This luminescence can be photographed with a special EL camera.
The modules are aligned in a darkroom parallel to the EL camera and connected to an electric DC power supply. A photograph is then taken at a temperature of between 20 and 25 degrees Celsius. The result is similar to an X-ray and also shows the smallest micro cracks and cell breakages. Defect areas appear darker than intact ones.
And by the way: Almost simultaneously with the EL imaging a performance test is also performed with a flasher (picture right). But more on this in one of our following blog articles!