Uncertainty analysis in contact resistivity measurements of crystalline silicon solar cells

Abstract

The achievement of obtaining low contact resistivity between silver electrodes and the emitter layer of a crystalline silicon solar cell has been a constant issue for the silver paste developers in crystalline silicon solar cell industries. However, it has been found that there are factors that significantly distort the accurate characterization of contact resistivity. One group of such factors have been identified to be not related with the physical traits of silver paste nor the size of a crystalline silicon solar cell wafer. These factors include mathematical formulations to calculate contact resistivity, the preparation method for specimens, probing methods, current source settings, and environmental conditions. On the other hand, the other group of such factors are directly related with the formulation method and composition of silver paste, and the size of a crystalline silicon solar cell wafer where specimens for the resistance measurements are prepared. Through this study, the impact of each factor on resistance measurement using a three-point probe method for the calculation of contact resistivity is analyzed.