717-MV OPEN-CIRCUIT VOLTAGE SILICON SOLAR-CELLS USING HOLE-CONSTRAINED SURFACE PASSIVATION

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/cm(2) at 25 degrees 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.