CC BY 4.0Weiss, CharlotteCharlotteWeissSchön, JonasJonasSchönHöhn, OliverOliverHöhnFuhrmann, B.B.FuhrmannDimroth, FrankFrankDimrothJanz, StefanStefanJanz2022-03-066.10.20212021https://publica.fraunhofer.de/handle/publica/26990410.1109/JPHOTOV.2021.3087727This article describes the successful integration of a passivated, highly reflecting Ge rear side into a III-V multijunction solar cell. The use of lowly doped Ge and the new rear side leads to the aimed increase in Ge cell current up to 1.6 mA.cm (exp -2), demonstrated by external quantum efficiency and I-V measurements. For the contact formation, two different types of laser processes were conducted and evaluated-the laser fired contact route and the PassDop route. In both cases, the formation of a local back surface field preserves the passivation of the contact points. A laser pitch and laser power variation leads to a good performing back contact. The passivation effect is proven experimentally and is qualitatively accessed with cell simulations.enPhotovoltaikgermaniumIII-V solar cellslaser contactspassivationSilicium-PhotovoltaikIII-V- und Konzentrator-PhotovoltaikEpitaxieSi-Folien und SiC-AbscheidungenOberflächen: KonditionierungPassivierungLichteinfangIII-V Epitaxie und Solarzellen621697journal article