Luminescence Shunt Imaging: Qualitative and Quantitative Shunt Images Using Photoluminescence Imaging

Abstract

In this paper, we present a proof of concept study for a quantitative method for shunt detection in silicon solar cells using photoluminescence imaging. The method is based on interpretation of the luminescence intensity around a local shunt in terms of the extracted current density. The theoretical relationship between the PL signal and the shunt current is derived. Experimental results on specifically prepared test structures, on intentionally shunted monocrystalline cells and on shunted industrial multicrystalline cells are presented and compared to shunt values from dark IV, SunsVoc and Lock in thermography. Good agreement is found for the test structures and for the intentionally shunted cells. For the multicrystalline cells the shunt values calculated from PL images agree to within a factor of two with shunt values obtained from other methods.