Characterisation of a LBIC system by scanning of silicon solar cells and modules

A laser beam induced current (LBIC) system has been used as a non-destructive characterisation tool for photovoltaic (PV) devices. It provides a detailed twodimensional map of the current signal. Each data point in the map is generated by the laser beam scanning over the devices. The signal strength depends on the response of that particular area on which the laser beam is incident, thereby reflecting the absorption and collection characteristics of that local PV area. However, the magnitude of the measured signal, induced by modulated laser, is very small. Adjustment of set parameters, measurement variables and environmental influences may affect the measurement result and thus could lead to misinterpretation. The LBIC system at the Centre for Renewable Energy Systems Technology (CREST) is analysed for reliability and optimised. It is evident that with appropriate settings under controlled environmental conditions, the system can provide a highly repeatable measurement result.