TY  - JOUR
A1  - Li, Tian-yi
A1  - Benduhn, Johannes
A1  - Qiao, Zhi
A1  - Liu, Yuan
A1  - Li, Yue
A1  - Shivhare, Rishi
A1  - Jaiser, Frank
A1  - Wang, Pei
A1  - Ma, Jie
A1  - Zeika, Olaf
A1  - Neher, Dieter
A1  - Mannsfeld, Stefan C. B.
A1  - Ma, Zaifei
A1  - Vandewal, Koen
A1  - Leo, Karl
T1  - Effect of H- and J-Aggregation on the Photophysical and Voltage Loss of Boron Dipyrromethene Small Molecules in Vacuum-Deposited Organic Solar Cells
T2  - The journal of physical chemistry letters
N2  - An understanding of the factors limiting the open-circuit voltage (V-oc) and related photon energy loss mechanisms is critical to increase the power conversion efficiency (PCE) of small-molecule organic solar cells (OSCs), especially those with near-infrared (NIR) absorbers. In this work, two NIR boron dipyrromethene (BODIPY) molecules are characterized for application in planar (PHJ) and bulk (BHJ) heterojunction OSCs. When two H atoms are substituted by F atoms on the peripheral phenyl rings of the molecules, the molecular aggregation type in the thin film changes from the H-type to J-type. For PHJ devices, the nonradiative voltage loss of 0.35 V in the J-aggregated BODIPY is lower than that of 0.49 V in the H-aggregated device. In BHJ devices with a nonradiative voltage loss of 0.35 V, a PCE of 5.5% is achieved with an external quantum efficiency (EQE) maximum of 68% at 700 nm.
Y1  - 2019
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/49070
SN  - 1948-7185
VL  - 10
IS  - 11
SP  - 2684
EP  - 2691
PB  - American Chemical Society
CY  - Washington
ER  -