title: Solution-processed parallel tandem polymer solar cells using silver nanowires as intermediate electrode.
abstract: Tandem architecture is the most relevant concept to overcome the efficiency limit of single-junction photovoltaic solar cells. Series-connected tandem polymer solar cells (PSCs) have advanced rapidly during the past decade. In contrast, the development of parallel-connected tandem cells is lagging far behind due to the big challenge in establishing an efficient interlayer with high transparency and high in-plane conductivity. Here, we report all-solution fabrication of parallel tandem PSCs using silver nanowires as intermediate charge collecting electrode. Through a rational interface design, a robust interlayer is established, enabling the efficient extraction and transport of electrons from subcells. The resulting parallel tandem cells exhibit high fill factors of ∼60% and enhanced current densities which are identical to the sum of the current densities of the subcells. These results suggest that solution-processed parallel tandem configuration provides an alternative avenue toward high performance photovoltaic devices.
authors.affiliation: Institute of Materials for Electronics and Energy Technology (I-MEET), University of Erlangen-Nuremberg , Martensstrasse 7, 91058 Erlangen, Germany.
authors.forename: Fei
authors.initials: F
authors.lastname: Guo
authors.forename: Peter
authors.initials: P
authors.lastname: Kubis
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Thomas
authors.initials: T
authors.lastname: Przybilla
authors.forename: Gebhard
authors.initials: G
authors.lastname: Matt
authors.forename: Tobias
authors.initials: T
authors.lastname: Stubhan
authors.forename: Tayebeh
authors.initials: T
authors.lastname: Ameri
authors.forename: Benjamin
authors.initials: B
authors.lastname: Butz
authors.forename: Erdmann
authors.initials: E
authors.lastname: Spiecker
authors.forename: Karen
authors.initials: K
authors.lastname: Forberich
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Brabec
keywords: parallel-tandem; polymer solar cells; silver nanowires; solution-processed