Bifacial n-type silicon solar cells for upconversion applications

Perimeter recombination causes significant efficiency loss in solar cells. This paper presents a method to quantify perimeter recombination via luminescence imaging for silicon solar cells embedded within the wafer. The validity of the method is discussed and verified via 2-D semiconductor simulation. We demonstrate the method to be sufficiently sensitive in that it can quantify perimeter recombination even in a solar cell where no obvious deviation from ideality is observed in the current–voltage (J–V) curve.

Perimeter Recombination Characterization by Luminescence Imaging

Edge isolation of solar cells using laser doping

Influence of plasma process on III-V/Ge multijunction solar cell via etching

The impact of via etching on triple junction solar cell performance has been investigated for through cell via contact architectures. Triple junction solar cells with standard top and back contacts have been fabricated and vias have been etched through the subcells to investigate the new geometry proposed. The external quantum efficiency, the open-circuit voltage ( V oc), the fill factor (FF), and the ideality factor have been measured and compared to those of standard triple junction solar cells without vias. In this way, we evaluate the losses attributable to via etching. Small performance losses from via integration are observed, but performance can be partially restored with an ammonium sulfide passivation treatment. Furthermore, the results show that the V oc losses are almost absent at the high sun concentration that the new architecture is designed for. The source of the performance degradation is correlated with a larger total surface recombination at the edges of the device. The passivation treatment allows an effective surface passivation of the via holes.

Impact of Via Hole Integration on Multijunction Solar Cells for Through Cell Via Contacts and Associated Passivation Treatment

This work shows experimentally the decrease in open-circuit voltage produced by edge recombination in silicon solar cells. The effect is related to the edge area to junction area ratio.

J. Eguren

Papers

Influence of the junction area to edge area ratio on the open-circuit voltage of silicon solar cells