New method for the direct measurement of solar cell junction ideality factor

A new method which can measure the junction ideality factor n directly from the J-V curve of an illuminated solar cell is described. The advantages of the method are that n can be obtained from the J-V curve of the illuminated solar cell directly without information about other parameters (shunt resistance, series resistance and saturation current densities) for high efficiency solar cells and without information about saturation current densities for low quality solar cells. Cases with different series resistance and shunt resistance are treated. The method is used to measure the junction ideality factor of MINP. MIS and n⁺/p silicon solar cells, which are fabricated in our laboraatory. The n values are in the range between 1 and 2, which are in agreement with theory.