Analysis of perimeter recombination in the subcells of GaInP/GaAs/Ge triple-junction solar cells

This paper studies the recombination at the perimeter in the subcells that constitute a GaInP/GaAs/Ge lattice-matched triple-junction solar cell. For that, diodes of different sizes and consequently different perimeter/area ratios have been manufactured in single-junction solar cells resembling the subcells in a triple-junction solar cell. It has been found that neither in GaInP nor in Ge solar cells the recombination at the perimeter is significant in devices as small as 500mx500m(2.510(-3)cm(2)) in GaInP and 250mx250m(6.2510(-4)cm(2)) in Ge. However, in GaAs, the recombination at the perimeter is not negligible at low voltages even in devices as large as 1cm(2), and it is the main limiting recombination factor in the open circuit voltage even at high concentrations in solar cells of 250mx250m(6.2510(-4)cm(2)) or smaller. Therefore, the recombination at the perimeter in GaAs should be taken into account when optimizing triple-junction solar cells. Copyright (c) 2014 John Wiley & Sons, Ltd.