title: High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes.
abstract: The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.
authors.affiliation: Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Luyao
authors.initials: L
authors.lastname: Lu
authors.affiliation: 1] Division of Materials Science, Argonne National Laboratory, Argonne, Illinois 60439, USA [2] Institute for Molecular Engineering, The University of Chicago, 5747 South Ellis Avenue, Chicago, Illinois 60637, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.affiliation: Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Luping
authors.initials: L
authors.lastname: Yu