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Conjugated Polymer–Assisted Grain Boundary Passivation for Efficient Inverted Planar Perovskite Solar Cells
摘要： Grain boundaries in lead halide perovskite films lead to increased recombination losses and decreased device stability under illumination due to defect-mediated ion migration. The effect of a conjugated polymer additive, poly(bithiophene imide) (PBTI), is investigated in the antisolvent treatment step in the perovskite film deposition by comprehensive characterization of perovskite film properties and the performance of inverted planar perovskite solar cells (PSCs). PBTI is found to be incorporated within grain boundaries, which results in an improvement in perovskite film crystallinity and reduced defects. The successful defect passivation by PBTI yields reduces recombination losses and consequently increases power conversion efficiency (PCE). In addition, it gives rise to improved photoluminescence stability and improved PSC stability under illumination which can be attributed to reduced ion migration. The optimal devices exhibit a PCE of 20.67% compared to 18.89% of control devices without PBTI, while they retain over 70% of the initial efficiency after 600 h under 1 sun illumination compared to 56% for the control devices.
关键词： halide perovskites,conjugated polymers,grain boundary passivation,nickel oxide
更新于2025-11-20 15:33:11
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Steady Enhancement in Photovoltaic Properties of Fluorine Functionalized Quinoxaline-Based Narrow Bandgap Polymer
摘要： To investigate the influence of fluoride phenyl side-chains onto a quinoxaline (Qx) unit on the photovoltaic performance of the narrow bandgap (NBG) photovoltaic polymers, herein, two novel NBG copolymers, PBDTT-DTQx and PBDTT-DTmFQx, were synthesized and characterized. 2-ethylhexylthiothiophene-substituted benzodithiophene (BDTT), 2,3-diphenylquinoxaline (DQx) [or 2,3-bis(3-fluorophenyl)quinoxaline (DmFQx)] and 2-ethylhexylthiophene (T) were used as the electron donor (D) unit, electron-withdrawing acceptor (A) unit and π-bridge, respectively. Compared to non-fluorine substituted PBDTT-DTQx, fluoride PBDTT-DTmFQx exhibited a wide UV-Vis absorption spectrum and high hole mobility. An enhanced short-circuit current (Jsc) and fill factor (FF) simultaneously gave rise to favorable efficiencies in the polymer/PC71BM-based polymer solar cells (PSCs). Under the illumination of AM 1.5G (100 mW cm?2), a maximum power conversion efficiency (PCE) of 6.40% was achieved with an open-circuit voltage (Voc) of 0.87 V, a Jsc of 12.0 mA cm?2 and a FF of 61.45% in PBDTT-DTmFQx/PC71BM-based PSCs, while PBDTT-DTQx-based devices also exhibited a PCE of 5.43%. The excellent results obtained demonstrate that PBDTT-DTmFQx by fluorine atom engineering could be a promising candidate for organic photovoltaics.
关键词： quinoxaline,synthesis,polymer solar cells,bulk heterojunction,narrow bandgap conjugated polymer
更新于2025-11-19 16:56:42
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Effect of concentration of DH6T on the performance of photoconductor fabricated using blends of P3HT and DH6T
摘要： The influence of small molecule (SM) α, ω-di-hexyl-sexithiophene (DH6T) concentration, in the blends of conjugated polymer (CP) poly (3-hexylthiophene) (P3HT) and DH6T, was investigated in terms of barrier potential reduction and improved photoresponse of the fabricated photoconductor using these blends. Barrier potential in Au/P3HT:DH6T/Au device structure, occurring at the interface of Au (top)/P3HT:DH6Twas estimated by Fowler Nordheim (FN) tunneling model-based analysis of I-V characteristics. The barrier potential of the fabricated device was observed to decrease upon addition of a small quantity of DH6T in comparison to the pristine polymer-based device. This reduction in barrier was attributed to the improved ordering and morphology of the polymer chains upon blending it with an SM. The variation in the ordering of the polymer chains was further confirmed with Photoluminescence spectroscopy, Absorption spectroscopy, and XRD data. Subsequently, it was also observed that only up to a definite SM concentration (25% in this study) ordering of polymer chains improved causing a reduction in barrier potential and subsequent improvement in the photoresponse of the fabricated devices. Finally, it was observed that the optimized blending of CP and SM could to be useful in reducing the effect of penetration of Au inside the CP matrix in the top contact configuration thereby resulting in the reduction of a barrier for carrier injection which is generally lower in the bottom contact configurations. These studies are critical from the point of view of the development of photoconductors and photosensitive top contact organic field effect transistors (OFETs).
关键词： Barrier potential,Small molecule,Photoconductor,Conjugated polymer
更新于2025-11-19 16:56:35
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Multi-scale ordering in highly stretchable polymer semiconducting films
摘要： Stretchable semiconducting polymers have been developed as a key component to enable skin-like wearable electronics, but their electrical performance must be improved to enable more advanced functionalities. Here, we report a solution processing approach that can achieve multi-scale ordering and alignment of conjugated polymers in stretchable semiconductors to substantially improve their charge carrier mobility. Using solution shearing with a patterned microtrench coating blade, macroscale alignment of conjugated-polymer nanostructures was achieved along the charge transport direction. In conjunction, the nanoscale spatial confinement aligns chain conformation and promotes short-range π–π ordering, substantially reducing the energetic barrier for charge carrier transport. As a result, the mobilities of stretchable conjugated-polymer films have been enhanced up to threefold and maintained under a strain up to 100%. This method may also serve as the basis for large-area manufacturing of stretchable semiconducting films, as demonstrated by the roll-to-roll coating of metre-scale films.
关键词： charge carrier mobility,conjugated polymers,solution shearing,stretchable semiconductors,roll-to-roll coating,multi-scale ordering
更新于2025-11-19 16:56:35
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Synthesis of π-conjugated poly(arylene)s by polycondensation of 1,4-bis(3-methylpyridin-2-yl)benzene and aryl dibromides through regiospecific C-H functionalization process
摘要： On the basis of the Ru-catalyzed regiospeci?c direct double arylation of benzene rings possessing 3-methylpyridin-2-yl substituents to produce 1-aryl-2-(3-methylpyridin-2-yl)benzene derivatives, the synthesis of poly(p-phenylene) derivatives having 2,5-bis(3-methylpyridin-2-yl) substituents is described. The reaction of 1,4-bis(3-methylpyridin-2-yl)benzene with bromobenzene (2 equiv) was carried out in the presence of [RuCl2(η6-C6H6)]2 (5 mol %) in 1-methyl-2-pyrrolidone at 120°C for 24 h to produce 1,4-bis(3-methylpyridin-2-yl)-2,5-diphenylbenzene in 99% yield as a sole product. Neither 2,6-diphenylated nor further phenylated products was produced under the examined conditions. This regiospeci?c double arylation process was then applied to the synthesis of π-conjugated polymers by use of aryl dibromides such as 1,4-dibromobenzene, 2,7-dibromo-9,9-dihexyl?uorene, and 2,5-dibromothiophene. For example, a polymer was obtained in 73% yield by using 1,4-dibromobenzene, whose Mn and Mw/Mn were estimated to be 3300 and 1.51, respectively. The bathochromic shift of the ultraviolet (UV)–visible absorption spectrum with respect to that of the model compound, 1,4-bis(3-methylpyridin-2-yl)-2,5-diphenylbenzene, indicated the extension of the π-conjugation. The blue ?uorescence was also observed for the polymer upon the UV irradiation.
关键词： C-H functionalization,direct double arylation,poly(arylene)s,π-conjugated polymers
更新于2025-11-19 16:46:39
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Conjugated helical polymers: End-group control and coupling reactions
摘要： Telechelic helical poly(phenyleneethynylene)s 2 and 3 bearing end iodo and ethynyl groups were synthesized by the Sonogashira–Hagihara coupling reaction of prepolymer 1 with N-α-tert-butoxycarbonyl-3,5-diiodo-4-hydroxy-D-phenylglycine hexylamide (4) and p-diethynylbenzene (5), respectively. Polymer 2 was treated by Sonogashira–Hagihara coupling reaction with 1,6-diethynylpyrene (a) and 4,4-diethynylbiphenyl (b) to obtain the corresponding polymers 2a and 2b. Polymer 2 was also subjected to the Mizoroki–Heck coupling reaction with diphenyl(p-vinylphenyl)phosphine (e) to obtain the corresponding polymer 2e, and the incorporation of the phosphine moieties was confirmed by 31P NMR spectroscopy. In a similar fashion, polymer 3 was polymerized with 1,4-dibromonaphthalene (c) and 9,10-dibromoanthracene (d), but no concrete evidence for the formation of polymers 3c and 3d was observed. Circular dichroism (CD) spectroscopic analysis revealed that all the polymers adopted folded helical conformations with predominantly one-handed screw sense in CHCl3. The polymers exhibited photoluminescence (PL) depending on the incorporated functional groups.
关键词： helical polymer,telechelic polymer,coupling reaction,conjugated polymer
更新于2025-11-19 16:46:39
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Time-dependent DFT and experimental study on visible light photocatalysis by metal oxides of Ti, V and Zn after complexing with a conjugated polymer
摘要： Density Functional Theory (DFT) and Time Dependent (TD)-DFT studies predict substantial modifications in optical properties of Transition Metal Oxides (TMOs) of Ti, V and Zn by complexing them with conjugated polymer polythiophene (PTh). The TMO nanostructures were synthesized and their complexes with polymers were fabricated using a chemical oxidative polymerization method. Coating of the TMOs with PTh and the nano-dimensional nature of the samples was confirmed by various morphological investigations such as infrared (IR), X-ray di?ractographs (XRD), High Resolution Transmission Electron Microscopy (HR-TEM) and field emission scanning electron microscopy (FE-SEM) techniques. The prepared samples were found to be a visible light driven photocatalyst. The sensitization of the complexes has been explained in terms of relative ordering of frontier orbitals of PTh and the TMO, and PTh qualified as an e?cient photosensitizer for all three metal oxides on the basis of its electronic characteristics. Since the Highest Occupied Molecular Orbital (HOMO) of PTh lies well between the band gap of all three TMOs, the electron transfer from donor (PTh) to acceptor (TMO) is facilitated. The appreciable red shift in the absorption spectrum and decrease in the optical band gap calculated by Tauc’s plot confirmed substantial reduction in the band gap of the formed complex in comparison to their bare counterparts. The isodensity plots established the PTh–TMO complexes as donor acceptor complexes and intermolecular charge transfer quantified the electron transfer from PTh (donor) to the TMOs (acceptor).
关键词： conjugated polymer,TD-DFT,visible light,metal oxides,DFT,photocatalysis,polythiophene,band gap tuning
更新于2025-11-14 17:04:02
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A novel fluorescent nanosensor based on small-sized conjugated polyelectrolyte dots for ultrasensitive detection of phytic acid
摘要： A novel nanosensor is developed for selective and highly sensitive detection of phytic acid (PA) based on small-sized conjugated polyelectrolyte dots (Pdots) fabricated from a new conjugated polymer (P1) by a modified reprecipitation method. P1 featuring a π-delocalized backbone bearing meta-substituted pyridyl groups can be endowed with enhanced flexibility and hence is beneficial for the synthesis of ultrasmall Pdots (i.e. Pdot-1, ~3.8 nm in average diameter) as well as for the binding of Fe3+, thus leading to the obvious fluorescence quenching of Pdot-1 (~444 nm) in the presence of Fe3+ via an electron transfer (ET) process. In addition, phytic acid with six phosphate groups exhibits strong chelating ability. When phytic acid is added, phytic acid readily binds to Fe3+ and the fluorescence of Pdot-1 around 444 nm can be recovered, rendering the supersensitive and selective sensing of PA. Under the optimum conditions, this ultra-small Pdot-based nanoprobe favors the fluorescent determination of PA with the detection limit as low as 10 nM. Particularly, Pdot-1 with bright blue fluorescence exhibits low cytotoxicity. Furthermore, the small-sized and biocompatible Pdot-1 can be applied to the sensitive fluorescence assay for PA in cell extracts and the efficient imaging of PA in live cells.
关键词： Fluorescence,Imaging,Small-sized conjugated polyelectrolyte dots,Phytic acid
更新于2025-11-14 15:29:11
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Glutaraldehyde non-conjugated chitosan polymer fluorophores for selective determination of picric acid via fluorescence resonance energy transfer strategy
摘要： Water-dispersed glutaraldehyde (GA) non-conjugated chitosan polymer fluorophores (GCPF) with quantum yield of 16 % is synthesized by stirring chitosan and GA for 6 h at room temperature in the present work. It is a facile and mild method and fluorescent GCPF can be stabled for two months. Owing to the spectral overlap of fluorescent spectrum of GCPF and absorption spectrum of picric acid (PA), a novel sensitive fluorescent method using fluorescent GCPF for PA detection from 10 nM to 50 μM via fluorescence resonance energy transfer (FRET) strategy is established. The distance between donor of GCPF and acceptor of PA (R0 value) is calculated to be 3.5 nm. FRET method using fluorescent GCPF possesses high sensitivity (LOD of 2.8 nM), and selectivity and fast response within 2 min. Moreover, fluorescent GCPF is also utilized in visual analysis of PA using cotton swabs. Fluorescence quenching effect can be observed by eyes irradiated with 365 nm ultraviolet light at cotton swabs and using GCPF solid on quartz glasses, which paves an effect and wide way for the application of fluorescent GCPF in our daily life.
关键词： Glutaraldehyde non-conjugated chitosan polymer fluorophores (GCPF),picric acid (PA),fluorescence resonance energy transfer (FRET),glutaraldehyde (GA),chitosan
更新于2025-11-14 15:23:50
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An experimental and theoretical study of the structural ordering of the PTB7 polymer at a mesoscopic scale
摘要： Our extensive study based on optoelectronic and electric measurements (which consisted of: UV-Vis absorption, photoluminescence, surface photovoltage measurement, charge extraction by linearly increasing voltage, and energy-resolved electrochemical impedance spectroscopy) revealed the fundamental role of the thickness of the formation of intra- and interchain interaction in poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}) (PTB7) films. We have shown that the final optoelectronic and electronic properties of PTB7 films are governed by the structural ordering development of the transition from nano- to submicroscale. The ordering of polymer chains and competition between the formation of J- and H-aggregates results in a non-trivial dependence of luminescence, exciton diffusion length, transport band gap, and defect concentration. According to a theoretical analysis, the driving forces responsible for the observed phenomena are associated with the thickness threshold dependence of the thin film drying mode which can proceed with or without the polymer skin formation on the surface of forming film.
关键词： low band-gap,thickness dependences,Conjugated polymers
更新于2025-10-22 19:40:53