69249-61-2Relevant articles and documents
Push-pull thiophene-based small molecules with donor and acceptor units of varying strength for photovoltaic application: Beyond P3HT and PCBM
Boschi, Alex,Candini, Andrea,Di Maria, Francesca,Gazzano, Massimo,Lanzi, Massimiliano,Marinelli, Martina,Monti, Filippo,Pierini, Filippo,Salatelli, Elisabetta,Zanelli, Alberto,Zangoli, Mattia
supporting information, p. 11216 - 11228 (2021/09/15)
Here is reported an expedient synthesis implementing enabling technologies of a family of thiophene-based heptamers alternating electron donor (D) and acceptor (A) units in a D-A′-D-A-D-A′-D sequence. The nature of the peripheral A groups (benzothiadiazole vs. thienopyrrole-dione vs. thiophene-S,S-dioxide) and the strength of the donor units (alkyl vs. thioalkyl substituted thiophene ring) have been varied to finely tune the chemical-physical properties of the D-A oligomers, to affect the packing arrangement in the solid-state as well as to enhance the photovoltaic performances. The optoelectronic properties of all compounds have been studied by means of optical spectroscopy, electrochemistry, and density functional theory calculations. Electrochemical measurements and Kelvin probe force microscopy (KPFM) predicted a bifunctional behaviour for these oligomers, suggesting the possibility of using them as donor materials when blended with PCBM, and as acceptor materials when coupled with P3HT. Investigation of their photovoltaic properties confirmed this unusual characteristic, and it is shown that the performance can be tuned by the different substitution pattern. Furthermore, thanks to their ambivalent character, binary non-fullerene small-molecule organic solar cells with negligible values of HOMO and LUMO offsets were also fabricated, resulting in PCEs ranging between 2.54-3.96%. This journal is
Planar and twisted molecular structure leads to the high brightness of semiconducting polymer nanoparticles for NIR-IIa fluorescence imaging
Liu, Shunjie,Ou, Hanlin,Li, Yuanyuan,Zhang, Haoke,Liu, Junkai,Lu, Xuefeng,Kwok, Ryan T.K.,Lam, Jacky W.Y.,Ding, Dan,Tang, Ben Zhong
supporting information, p. 15146 - 15156 (2020/10/13)
Semiconducting polymer nanoparticles (SPNs) emitting in the second near-infrared window (NIR-II, 1000-1700 nm) are promising materials for deep-tissue optical imaging in mammals, but the brightness is far from satisfactory. Herein, we developed a molecular design strategy to boost the brightness of NIR-II SPNs: structure planarization and twisting. By integration of the strong absorption coefficient inherited from planar π-conjugated units and high solid-state quantum yield (φPL) from twisted motifs into one polymer, a rise in brightness was obtained. The resulting pNIR-4 with both twisted and planar structure displayed improved φPL and absorption when compared to the planar polymer pNIR-1 and the twisted polymer pNIR-2. Given the emission tail extending into the NIR-IIa region (1300-1400 nm) of the pNIR-4 nanoparticles, NIR-IIa fluorescence imaging of blood vessels with enhanced clarity was observed. Moreover, a pH-responsive poly(β-amino ester) made pNIR-4 specifically accumulate at tumor sites, allowing NIR-IIa fluorescence image-guided cancer precision resection. This study provides a molecular design strategy for developing highly bright fluorophores.
Single-material organic solar cells with fully conjugated electron-donor alkoxy-substituted bithiophene units and electron-acceptor benzothiadiazole moieties alternating in the main chain
Di Maria, Francesca,Lanzi, Massimiliano,Liscio, Andrea,Marinelli, Martina,Salatelli, Elisabetta,Zanelli, Alberto,Zangoli, Mattia
supporting information, p. 4124 - 4132 (2020/04/15)
Main chain conjugated linear polymers, constituted by alternating electron-donor (D) and-acceptor (A) moieties, have been prepared with the aim of testing their performances as photoactive components in single material organic solar cells (SMOSCs). The D moiety is constituted by bithiophene co-units bearing in position 3 of the thiophene ring a hexyloxy, a hexyloxymethyl or a hexyl group, while the A moiety is represented by the benzothiadiazole group. The D-A polymers were obtained in high yield through the poorly demanding oxidative FeCl3 polymerization process-starting, respectively, from the related precursors 4,7-bis(3-hexyloxythiophen-2-yl)benzo[c][2,1,3]thiadiazole, 4,7-bis[3-(6-methoxyhexyl)thiophen-2-yl]benzo[c][2,1,3]thiadiazole and 4,7-bis(3-hexylthiophen-2-yl)benzo[c][2,1,3]thiadiazole-with low dispersity indexes, close to the monodisperse state, after fractionation with methanol. The materials have been thoroughly characterized for their physical and structural properties and then tested for photoconversion efficiency in SMOSCs by using different deposition procedures of the photoactive component. In agreement with Kelvin probe force microscopy (KPFM) measurements, the best photovoltaic performance was observed for the polymer based on conjugated 3-alkoxythiophene and benzothiadiazole moieties, achieving significant photocurrents for this type of fully conjugated alternating D-A structure (Jsc = 2.63-3.72 mA cm-2).
