Purification and electronic characterisation of 18 isomers of the OPV acceptor material bis-[60]PCBM

Abstract

The as-produced isomer mixture of the organic photovoltaic device acceptor material bis-[60]PCBM has been purified into its constituents by peak-recycling HPLC, and those individual isomers were characterised by UV-Vis absorption spectroscopy and cyclic voltammetry. A total of 18 isomers were purified from the mixture to a standard exceeding 99.5% with respect to other isomers. The HOMOs, LUMOs, and HOMO-LUMO gaps of the purified isomers vary from -5.673 to -5.444 eV, -3.901 to -3.729 eV, and 1.664 to 1.883 eV, respectively. We also find a correlation between HPLC retention time and the relative positions of the addends; in that generally the closer the addends are to each other the longer the retention time of the isomer, and vice versa.

Isomer‐Pure Bis‐PCBM‐Assisted Crystal Engineering of Perovskite Solar Cells Showing Excellent Efficiency and Stability

“…Recently, 18 isomers from the mixture have been purified by preparative peak‐recycling, high‐performance liquid chromatography (HPLC) . Herein, we have employed the most abundant of those isomers, α‐bis‐PCBM (Figure S1, Supporting Information), as a templating agent in chlorobenzene antisolvent, to enhance the electronic quality and PV performance of solution processed perovskite films.…”

Structural Identification of 19 Purified Isomers of the OPV Acceptor Material bisPCBM by 13C NMR and UV–Vis Absorption Spectroscopy and High-Performance Liquid Chromatography

“…The UV-Vis absorption spectra show that the trans-1 'polar' isomers and the e 'equatorial' isomers each form a group of two similar but distinguishable isomers, and that those for the other bond-types (trans-3, trans-4, cis-3 and cis-2) each form a bond-type group with three members. 4 This observation may be explained by Table 1.…”

“…200 meV above that of PCBM), is particularly promising. 4 The most abundant isomer of bis[60]PCBM has recently been incorporated in a perovskite-based photovoltaic device in pure form. 13 This device had a high power conversion efficiency of 20.8%, which is substantially higher than similar devices based on (a) the pristine perovskite or (b) [60]PCBM treated perovskite.…”

In‐depth probe of researching interfacial charge transfer process for organic solar cells: A promising bisadduct fullerene derivatives acceptor

“…The other one is to change the substituent groups and the number of fullerene derivatives, introducing multiple functional groups to increase the lowest unoccupied molecular orbital (LUMO) energy level, essentially to enhance absorption range and V OC . Further, considering the influence of the disorder on energy and the hybridization on carbon cages packing density, bisadducts containing heteroatoms that facilitate electron transport, such as Bis‐TOQC, have received extensive attention . For Bis‐TOQC, double thieno‐o‐quinodimethane groups (TOQC) on the carbon cage improve compatibility of D and A as well as improve the LUMO energy level to promote absorption in the visible region compared to its monosubstituted material (Mono‐TOQC).…”

“…[11] Further, considering the influence of the disorder on energy and the hybridization on carbon cages packing density, bisadducts containing heteroatoms that facilitate electron transport, such as Bis-TOQC, have received extensive attention. [12,13] For Bis-TOQC, double thieno-o-quinodimethane groups (TOQC) on the carbon cage improve compatibility of D and A as well as improve the LUMO energy level to promote absorption in the visible region compared to its monosubstituted material (Mono-TOQC). Notably, although it has been proved superior to Mono-TOQC, there are still confusions as to whether Bis-TOQC could be applied to the research of interface photoelectric conversion process like PC 61 BM and whether the compound obtained by replacing C 60 with C 70 in Bis-TOQC will have better properties relative to PC 71 BM.…”