Quasi‐2D perovskites are attractive because of their improved stability compared with 3D perovskites counterparts; however, they suffer from poor performance due to the insulating organic cation spacers. To resolve this issue, a strategy of replacing the insulating spacer with conducting spacer is proposed which successfully converts the spacer from a charge‐transporting “barrier” to charge‐transporting “bridge.” Specifically, an alkyl linker‐free, fully conjugated aromatic 2,2′‐biimidazolium (BIDZ) cation is introduced as a spacer to compose quasi‐2D perovskites. Density functional theory (DFT) simulation results show that the lowest unoccupied molecular orbital (LUMO) level localizes on BIDZ and the highest occupied molecular orbital (HOMO) level is on the perovskite. However, both HOMO and LUMO levels localize on perovskite slabs for the well‐known phenethylammonium (PEA)‐based 2D perovskites. The strong electronic coupling between BIDZ and 3D perovskite slabs improves carrier mobilities even for a low‐weak‐crystallinity and random‐orientated quasi‐2D perovskite film. As a result, a remarkable power conversion efficiency up to 11.4% (
Four cross‐conjugated molecules based on the benzo[1,2‐
- NSF-PAR ID:
- 10236009
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Asian Journal of Organic Chemistry
- Volume:
- 10
- Issue:
- 1
- ISSN:
- 2193-5807
- Page Range / eLocation ID:
- p. 215-223
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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n = 5) is achieved, which is much higher than that of PEA‐based random‐orientated quasi‐2D perovskites with the same processing condition (6.5%). The strategy paves the way to highly efficient and stable quasi‐2D perovskites solar cells through designing new organic spacer cations. -
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Abstract ipso ‐Arylative ring‐opening polymerization of 2‐bromo‐8‐aryl‐8H ‐indeno[2,1‐b]thiophen‐8‐ol monomers proceeds to Mnup to 9 kg mol−1with conversion of the monomer diarylcarbinol groups to pendent conjugated aroylphenyl side chains (2‐benzoylphenyl or 2‐(4‐hexylbenzoyl)phenyl), which influence the optical and electronic properties of the resulting polythiophenes. Poly(3‐(2‐(4‐hexylbenzoyl)phenyl)thiophene) was found to have lower frontier orbital energy levels (HOMO/LUMO=−5.9/−4.0 eV) than poly(3‐hexylthiophene) owing to the electron‐withdrawing ability of the aryl ketone side chains. The electron mobility (ca. 2×10−3 cm2 V−1 s−1) for poly(3‐(2‐(4‐hexylbenzoyl)phenyl)thiophene) was found to be significantly higher than the hole mobility (ca. 8×10−6 cm2 V−1 s−1), which suggests such polymers are candidates for n‐type organic semiconductors. Density functional theory calculations suggest that backbone distortion resulting from side‐chain steric interactions could be a key factor influencing charge mobilities. -
Abstract Achieving high electrical conductivity and thermoelectric power factor simultaneously for n‐type organic thermoelectrics is still challenging. By constructing two new acceptor‐acceptor n‐type conjugated polymers with different backbones and introducing the 3,4,5‐trimethoxyphenyl group to form the new n‐type dopant 1,3‐dimethyl‐2‐(3,4,5‐trimethoxyphenyl)‐2,3‐dihydro‐1
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