%P 050002-1-050002-6 %R 10.1063/1.4931510 %B AIP Conference Proceedings %T Why can't I measure the external quantum efficiency of the Ge subcell of my multijunction solar cell? %I Ies %X The measurement of the external quantum efficiency (EQE) of low bandgap subcells in a multijunction solar cell can be sometimes problematic. In particular, this paper describes a set of cases where the EQE of a Ge subcell in a conventional GaInP/GaInAs/Ge triple-junction solar cell cannot be fully measured. We describe the way to identify each case by tracing the I-V curve under the same light-bias conditions applied for the EQE measurement, together with the strategies that could be implemented to attain the best possible measurement of the EQE of the Ge subcell. %A Enrique Barrigón Montañés %A Pilar Espinet González %A Yedileth Contreras %A Ignacio del Rey Llorente %C Aix-les-Bains, France %J AIP Conference Proceedings %L upm40905 %D 2015 %V 1679