@article{upm40866,
           title = {Implications of low breakdown voltage of component subcells on external quantum efficiency measurements of multijunction solar cells},
          volume = {23},
             doi = {10.1002/pip.2597},
       publisher = {Wiley Online Library},
         journal = {Progress in Photovoltaics},
           month = {November},
          number = {11},
            year = {2015},
           pages = {1597--1607},
            issn = {1062-7995},
             url = {http://onlinelibrary.wiley.com/doi/10.1002/pip.2597/abstract;jsessionid=EDED821223570CC20693BD6458752306.f02t02},
        abstract = {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.},
          author = {Barrig{\'o}n Monta{\~n}{\'e}s, Enrique and Espinet Gonz{\'a}lez, Pilar and Contreras, Yedileth and Rey-Stolle Prado, Ignacio},
        keywords = {Ge subcell; breakdown voltage; external quantum efficiency; multijunction solar cells}
}