The Recombination Parameter J0

The parameter J0, commonly used in solar cell modelling, has a deep physical meaning, which this paper intends to clarify. Upon examination, J0 can be identified as the recombination current density in thermal equilibrium. In many cases the same equilibrium parameter J0 can be used to describe carrier recombination under external illumination. Nevertheless, when carriers flow from the point where they are generated towards a high recombination site the value of J0 that matters to solar cell operation differs from that in equilibrium. In addition, J0 may in certain cases be dependent on the excess carrier concentration. We conclude by recommending that J0 be referred to as a recombination parameter.