The silicon solar cell will emit weakly infrared light if it connects to the power supply. This illumination can be registered by IR sensitive camera. It is used for solar cells defect detecting.

So the electroluminescence makes it possible to detect and distinguish most defects of solar cell (cracks, micro-cracks, fingers interrupts, low efficiency regions, higher series resistivity, low lifetime regions, short circuit, regions which were fired at non optimal temperature etc.) This method is nondestructive which take picture of solar cells by principle “dark region - trouble region”.

You can find bellow examples of electroluminescence images of solar cells, its fragments, solar strings and modules.

The measuring photoelectric parameters of solar cells and modules is a necessary step of it production. It is made under AM1,5 spectrum light with light power of 10000 W/m². The current-voltage characteristic (I-V curve) is obtained by varying supplied to solar cell (or module) voltage during illumination. The calculation of row data from I-V curve and temperature is made to give main parameters of current solar cell (or module).

There is a real I-V curve of silicon solar cell fragment is showed on the picture below. At right side of picture you can see the main parameters and its values.

The real I-V curve of silicon solar cell fragment