Differences between Electroluminescence (EL) and Photoluminescence (PL) Inspection

	Electroluminescence	Photoluminescence
Requirements	Electrical contacts are necessary.	No electrical contacts needed.
Substrates	Solar cells, strings, modules	Wafers, solar cells
Materials	mono-Si, poly-Si, a-Si, micro-Si, CIGS, CIS, CdTe	mono-Si, poly-Si
Measurement time	0.5-1 sec for mono-Si or poly-Si	0.5-2 sec for mono-Si, poly-Si
Informative value	Cracks, shunts, finger defects, deposition problems, bad edge isolation, ...	Similiar to EL, problems of the electrical grid system typically not visible

Advantages of Electroluminescence (EL) and Photoluminescence

EL and PL are non-destructive methods
Measurements deliver detailed information about defects and their location
EL and PL provide a high informative content, many types of defects can be clearly identified
Fast measurement on a second timescale
EL can be used to investigate small cells as well as large areas made from mono-Si, poly-Si, a-Si, micro-Si, CIGS, CIS, CdTe
Method can be integrated in the production process (in-line)
EL and PL are also well suited for research and development of new photovoltaic devices

Solar cells and solar modules suffer from a variety of invisible defects which reduce their output power and long-term stability. The highly sensitive Inspection Systems from greateyes image these problems. This allows you to optimize the production, increase output power and reduce overall costs