TY - JOUR KW - Ge subcell; breakdown voltage; external quantum efficiency; multijunction solar cells SN - 1062-7995 A1 - Barrigón Montañés, Enrique A1 - Espinet González, Pilar A1 - Contreras, Yedileth A1 - Rey-Stolle Prado, Ignacio Y1 - 2015/11// AV - public N2 - The electrical and optical coupling between subcells in a multijunction solar cell affects its external quantum efficiency (EQE) measurement. In this study, we show how a low breakdown voltage of a component subcell impacts the EQE determination of a multijunction solar cell and demands the use of a finely adjusted external voltage bias. The optimum voltage bias for the EQE measurement of a Ge subcell in two different GaInP/GaInAs/Ge triple-junction solar cells is determined both by sweeping the external voltage bias and by tracing the I?V curve under the same light bias conditions applied during the EQE measurement. It is shown that the I?V curve gives rapid and valuable information about the adequate light and voltage bias needed, and also helps to detect problems associated with non-ideal I?V curves that might affect the EQE measurement. The results also show that, if a non-optimum voltage bias is applied, a measurement artifact can result. Only when the problems associated with a non-ideal I?V curve and/or a low breakdown voltage have been discarded, the measurement artifacts, if any, can be attributed to other effects such as luminescent coupling between subcells. PB - Wiley Online Library IS - 11 VL - 23 ID - upm40866 TI - Implications of low breakdown voltage of component subcells on external quantum efficiency measurements of multijunction solar cells JF - Progress in Photovoltaics UR - http://onlinelibrary.wiley.com/doi/10.1002/pip.2597/abstract;jsessionid=EDED821223570CC20693BD6458752306.f02t02 EP - 1607 SP - 1597 ER -