Evaluation of protocols for temperature coefficient determination

The temperature coefficients of CIGS and c-Si modules were determined using both a Class C sun simulator and a Class A+ flash tester. The temperature coefficients were calculated following various light soaking procedures, and varying the heating and cooling ramps. The temperature coefficient determination was also carried out for bare cells (without lamination), and the results compared to measurements carried out on related modules. It was observed that in order to obtain a reliable value for the temperature coefficient, hysteresis effects in the performance as a function of temperature must be avoided.