SPLTRAK Abstract Submission
Perimeter recombination in GaAs solar cells with different geometries
Natasha Gruginskie, Gerard Bauhuis, Peter Mulder, Elias Vlieg, John Schermer
Radboud University, Nijmegen, Netherlands

In this study, we evaluate the effects of perimeter recombination to the performance of GaAs solar cells with different geometries. Two wafers with identical epi-structures were processed into both thin-film and substrate-based devices, which allowed the precise determination of the effect of a rear mirror as well as of the thin-film processing steps to the cells output. In each wafer, a series of solar cells with varying areas was fabricated, and the different contributions to the solar cells dark currents were extracted. We observed that, aside from an expected lower J01, the thin-film devices also showed a larger reduction in illuminated performance with decreasing cell area. From these results, we demonstrate that, in high quality solar cells with low interface recombination velocities and high photon recycling factors, the power output is limited by J02, which is highly affected by perimeter recombination. Therefore, the employment of perimeter passivation techniques might become necessary for these solar cells to achieve higher efficiencies, particularly in small scale applications.