Overcoming Interfacial Losses in Solution-Processed Organic Multi-Junction Solar Cells

Du X, Lytken O, Killian M, Cao J, Stubhan T, Turbiez M, Schmuki P, Steinrück HP, Ding L, Fink R, Li N, Brabec C (2016)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2016


Publisher: Wiley-VCH Verlag

DOI: 10.1002/aenm.201601959


Organic solar cells are promising in terms of full-solution-processing which enables low-cost and large-scale fabrication. While single-junction solar cells have seen a boost in power conversion efficiency (PCE), multi-junction solar cells are promising to further enhance the PCE. In all-solution-processed multi-junction solar cells, interfacial losses are often encountered between hole-transporting layer (HTL) and the active layers and therefore greatly limit the application of newly developed high-performance donor and acceptor materials in multi-junction solar cells. Here, the authors report on a systematic study of interface losses in both single-junction and multi-junction solar cells based on representative polymer donors and HTLs using electron spectroscopy and time-of-flight secondary ion mass spectrometry. It is found that a facile mixed HTL containing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and MoO nanoparticles successfully overcomes the interfacial losses in both single- and multi-junction solar cells based on various active layers by reducing interface protonation, promoting better energy-level alignment, and forming a dense and smooth layer. Solution-processed single-junction solar cells are demonstrated to reach the same performance as with evaporated MoO (over 7%). Multi-junction solar cells with polymers containing nitrogen atoms as the first layer and the mixed PEDOT:PSS and MoO nanoparticles as hole extraction layer reach fill factor (FF) of over 60%, and PCE of over 8%, while the identical stack with pristine PEDOT:PSS or MoO nanoparticles show FF smaller than 50% and PCE less than 5%.

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Du, X., Lytken, O., Killian, M., Cao, J., Stubhan, T., Turbiez, M.,... Brabec, C. (2016). Overcoming Interfacial Losses in Solution-Processed Organic Multi-Junction Solar Cells. Advanced Energy Materials. https://doi.org/10.1002/aenm.201601959


Du, Xiaoyan, et al. "Overcoming Interfacial Losses in Solution-Processed Organic Multi-Junction Solar Cells." Advanced Energy Materials (2016).

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