Controlled self-aggregation of perylene bisimide and its application in thick photoconductive interlayers for high performance polymer solar cells

Abstract

Highly conductive cathode interlayers are essential important for polymer solar cells that can work efficiently when the film is thick, which facilitates the massive production in future. Herein, an asymmetric organic dye molecule, perylene bisimide (PBI) 3, is synthesized as the photosensitizer for zinc oxide (ZnO) to achieve photoconductive hybrid material. The self-aggregation of PBI3 was efficiently restricted by the introduction of an alkyl group at one of the imide position in the molecule structure, while the formation of Zn-N chemical bonding between ZnO and PBI3 ensures the formation of robust hybrid thin film. The photoconductive hybrid thin film shows highly enhanced conductivity under white light irradiation. Inverted polymer solar cells (PSCs) based on the photoconductive cathode interlayers (ZnO:PBI3(3wt%)) shows very high power conversion efficiency (PCE) of 8.79% when the thickness of the interlayer is 100 nm, which is three times higher than that of the ZnO cathode interlayer based device.

Amino acid functionalised perylene bisimides for aqueous solution-deposited electron transporting interlayers in organic photovoltaic devices

“…Zhao et al showed that an asymmetric PBI enhanced the photoconductivity when used to dope the ZnO layer and this contributed to increased efficiency of PTB7/PC 71 BM based OPVs. 44 When the photoconductivity of the amino acid appended PBIs was studied, PBI-F, PBI-Y and PBI-W showed the lowest photoconductivity, indicating that radical anions (or dianions) were not readily formed under illumination. 24 Notably, it is these materials that are used in the highest performing OPV devices, and indeed exhibit the highest open-circuit voltages.…”

Spin–Orbit Charge‐Transfer Intersystem Crossing in Anthracene–Perylenebisimide Compact Electron Donor–Acceptor Dyads and Triads and Photochemical Dianion Formation

“…In this respect, perylenebisimide (PBI)i sa ni nteresting chromophored ue to its excellent thermala nd opticals tabilities, [59,60] high molar absorption coefficient, [61] reversible redox properties, [48,[62][63][64][65] and feasible derivatization chemistry. [66] These features make PBI av ersatile chromophorei nt he field of photovoltaics, [67] artificial photosynthesis, [68] and CS studies. [64,[69][70][71][72] However,m ost of the previouss tudies focusedo n the fluorescent properties of the PBI chromophore, and its triplet-state behavior remainsu nrevealed to alarge extent.…”

An In-Situ Reaction Route to Molecular Level Dispersed Bisimide and ZnO Nanorod Hybrids with Efficient Photo-Induced Charge Transfer

“…Among the ZnO-based organic-inorganic hybrids, perylene/ZnO hybrids as photoconductive hybrid materials were intensively studied [14][15][16][17][18] and showed very promising applications as cathode interlayer for high-performance solar cells. However, it is still challenging to obtain highly dispersed (molecular level) perylene/ZnO hybrids due to strong pi-pi stacking of perylene-induced phase separation between perylenes and ZnO [19]. On another hand, molecular level hybridization between perylene and ZnO will be helpful for efficient charge transfer in the hybrids, which has a large impact on photovoltaic property of materials, which is therefore essential to their applications in photovoltaics field [20][21][22].…”