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A simple model based on the simulation of distributed series resistance effects in solar cells is presented. This model overcomes limitations of the standard two-diode model representation of solar cells in respect to fitting Suns-Voc (m-Voc) and Jsc-Suns curves. The model results include (i) an improved understanding of two-dimensional current flows in shunted solar cells, (ii) the prediction of shunt types from m-Voc curves and corresponding distributed resistance model fits, (iii) the insight that lateral current flows in solar cells are responsible for deviations between Jsc-Suns data and twodiode model fits in the high illumination range. The presented approach extends the application range of Suns-Voc measurements to solar cells which cannot adequately be described with the two-diode model.

A virtual saturation of the supply of holes leading to an injection level dependent reduction in surface recombination velocity has been shown to be responsible for the improved performance of recent high efficiency silicon solar cells. By fabricating test cells taking advantage of this and other recombination reduction mechanisms, improved open-circuit voltages of 717 mV have been independently confirmed for experimental silicon cells. These voltages correspond to saturation current densities of 25 fA/cm2 at 25 °C, also the lowest demonstrated for a silicon junction device. Further improvement in both voltage and cell efficiency is expected to result from this work.

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