Efficiency Gain Analysis of Silicon Passivated Emitter and Rear Solar Cells Solely Based on Measurements

We present an approach to analyze and identify the predominant loss mechanisms in silicon solar cells. For this end, all losses are converted to potential efficiency gains and are thus directly comparable to one another as a derivative-like quantity. This derivative-like nature of the gains is validated at the hands of numerical simulations, showing that the formulary of the method basically calculates the derivatives of the efficiency with regard to the input parameters. The approach is solely based on measured data alone and recombination currents are measured at maximum power point like conditions. It is the first method to combine all these characteristics and is exemplarily applied to passivated emitter and rear cells (PERC) based on p-type mono- and multicrystalline silicon wafers. For our examined solar cells, we identify as bottlenecks the optical and recombination properties of the front side metallization in case of the monocrystalline PERC cell and the reflection at the active area in the multicrystalline case with potential efficiency gains of 1.2% abs and 1.6% abs , respectively