Graphene – a novel contact material
We applied large area graphene as contacts in Si-based solar cells with methyl-passivation (A)  and with poly-(3-hexyl)thiophene emitter (B)  with enhanced external quantum efficiencies (EQE) due to less light absorption by the graphene.
Additionally, graphene was also used in perovskite based solar cell devices in single (C)  and tandem structure (D) configurations  leading to a doping of graphene induced by the perovskite layer.
 Temperature and light dependent electrical properties of Graphene/n-Si–CH3-terminated solar cells; Brus, V.V.; Gluba, M.A.; Zhang, X.; Hinrichs, K.; Rappich, J.; Nickel, N.H.; Solar Energy 107 (2014) 74–81.
 Characterization of hybrid solar cells prepared from poly-thiophenes and silicon; Zellmeier, Matthias; Thesis at Humboldt Universität zu Berlin.
 In situ graphene doping as a route toward efficient perovskite tandem solar cells; Lang, F.; Gluba, M.A.; Shargaieva, O.; Rappich, J.; Korte, L.; Rech, B.; Nickel, N.H.; Phys. Status Solidi A 213 (2016) 1989-1996.
 Perovskite Solar Cells with Large-Area CVD-Graphene for Tandem Solar Cells; Lang, F.; Gluba, M.A.; Albrecht, S.; Rappich, J.; Korte, L.; Rech, B.; Nickel, N.H.; J. Phys. Chem. Lett. 6 (2015) 2745–2750.