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Does the probing of silicon solar cells really matter?

Reliable measurement of the electrical performance of a commercial-grade Si solar cell is a great matter of concern for manufacturers, project developers and investors. Therefore, the International Electrotechnical Commission (IEC) has laid down the standard procedures for solar cell performance measurement listed in IEC 60904 -1-10. However, shadow generated due to the fixed width of probing bars followed by difference in width of probe and bus bars introduce uncertainty in the short circuit current measurement and has not been standardized yet. A team of researchers led by Dr Ashok Kumar Sharma at NCPRE-crystalline silicon laboratory conducted a study focusing on the measurement uncertainty on solar cells carrying dissimilar dimension of bus bars. Investigation emphasized an essential requirement of correction known as shadow correction to minimize the measurement uncertainty. NCPRE researchers designed a set of kelvin probes to measure the short circuit current under the non-shadow condition and later used to apply the correction. “The proposed approach will help to mitigate the measurement uncertainties of solar cells efficiencies when tested at different laboratories or testing facilities, said Dr Sharma”.

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