Charge Photogeneration and Recombination in Mesostructured CuSCN-Nanowire/PC70 BM Solar Cells
Balawi, Ahmed H.
Anthopoulos, Thomas D.
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
KAUST Solar Center (KSC)
Core Lab, King Abdullah University of Science and Technology (KAUST); Thuwal 23955-6900 Saudi Arabia
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AbstractFullerene‐based materials are widely used as electron acceptors in organic bulk‐heterojunction solar cells; yet, they have rarely been used as the only photoactive component due to their low absorbance and limited charge generation efficiency. However, blending the wide‐bandgap p‐type material copper (I) thiocyanate (CuSCN) with [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC70BM) leads to the formation of a unique mesostructured p‐n like heterointerface between CuSCN and PC70BM and solar cells with a power conversion efficiency (PCE) of up to 5.4%. Here, we examine in detail the reasons for the surprisingly good device performance and elucidate the charge photogeneration and recombination mechanisms in CuSCN‐based devices with PC70BM as the exclusive light‐absorbing material. Our studies clearly demonstrate that a substantial fraction of the photocurrent in the CuSCN‐based devices results from improved dissociation of fullerene excitons and efficient charge transfer at the CuSCN:PC70BM interface combined with reduced geminate and nongeminate charge recombination losses. Our results have implications beyond the fullerene‐based devices studied here, as they demonstrate that careful selection of a mesostructured p‐type transparent semiconductor paves the path to a new type of efficient single photoactive material solar cells.
CitationFirdaus Y, Seitkhan A, Eisner F, Sit W-Y, Kan Z, et al. (2018) Charge Photogeneration and Recombination in Mesostructured CuSCN-Nanowire/PC70 BM Solar Cells. Solar RRL: 1800095. Available: http://dx.doi.org/10.1002/solr.201800095.
SponsorsY.F. and A.S. contributed equally to this work. The authors acknowledge the King Abdullah University of Science and Technology (KAUST) for the financial support.