Publication

Abstract : The spectral response of photoluminescence is a contactless method that provides a measurement of the relative external quantum efficiency of silicon solar cells and wafers. This method is accurate only if the measured luminescence originates from the radiative recombination of voltage dependent carriers. This paper investigates the impact of luminescence from voltage independent carriers in heavily diffused regions and other spurious sources of luminescence, such as luminescence from dielectric layers. A method, based on partial shading, is then demonstrated to record luminescence from only the voltage dependent carriers. This method is shown to provide accurate relative external quantum efficiency on cells and partially processed wafers. The relevance of the dependence of the measured data on the angular distribution of the incident light is demonstrated in this context, which explains errors in previously published data.