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Conjugated Polymers Based on Thiazole Flanked Naphthalene Diimide for Unipolar n-Type Organic Field-Effect Transistors
摘要： This paper reports the rational design and synthesis of a novel electron-withdrawing building block, thiazole flanked naphthalene diimide (TzNDI), which offers a coplanar conformation and deep-lying highest occupied molecular orbitals energy level in resulting conjugated polymers. A series of conjugated polymers (PTzNDI-2FT, PTzNDI-T, PTzNDI-Se, and PTzNDI-2T) consisting of TzNDI and different donor units were synthesized and characterized. The polymers all possess a high molecular weight and excellent thermal property. Their intense light absorption in low energy bands suggests an enhanced intramolecular charge transfer. The organic field-effect transistors (OFETs) based on these polymers exhibit unipolar n-type transport characteristics with low off current and high on–off current ratio. More importantly, all the devices exhibit near ideal transfer curves with kink-free transfer characteristics. Among these polymers, PTzNDI-2FT exhibits the highest electron mobility (μe) of 0.57 cm2 V?1 s?1, outperforming the commercial n-type polymer N2200 (0.41 cm2 V?1 s?1) under the same conditions. These results demonstrate that TzNDI is a promising building block for high performance unipolar n-type conjugated polymers in OFETs.
关键词： Unipolar n-Type,Thiazole Flanked Naphthalene Diimide,Conjugated Polymers,Organic Field-Effect Transistors
更新于2025-09-23 15:21:21
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Transparent-to-dark photo- and electrochromic gels
摘要： Smart windows in which the transmittance can be controlled on demand are a promising solution for the reduction of energy use in buildings. Windows are often the most energy inefficient part of a building, and so controlling the transmittance has the potential to significantly improve heating costs. Whilst numerous approaches exist, many suitable materials are costly to manufacture and process and so new materials could have a significant impact. Here we describe a gel-based device which is both photo- and electrochromic. The gel matrix is formed by the self-assembly of a naphthalene diimide. The radical anion of the naphthalene diimide can be formed photo or electrochemically, and leads to a desirable transition from transparent to black. The speed of response, low potential needed to generate the radical anion, cyclability of the system, temperature stability and low cost mean these devices may be suitable for applications in smart windows.
关键词： Smart windows,Gel-based device,Naphthalene diimide,Electrochromic,Photochromic
更新于2025-09-23 15:21:01
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Effects of a Fluorinated Donor Polymer on the Morphology, Photophysics, and Performance of All-Polymer Solar Cells based on Naphthalene Diimide-Arylene Copolymer Acceptors
摘要： Naphthalene diimide (NDI)-biselenophene copolymer (PNDIBS) and NDI-selenophene copolymer (PNDIS) and the fluorinated donor polymer PM6 were used to investigate how a fluorinated polymer component affects the morphology and performance of all-polymer solar cells (all-PSCs). Although the PM6:PNDIBS blend system exhibits a high open-circuit voltage (Voc = 0.925 V) and desired low optical bandgap energy loss (Eloss = 0.475 eV), the overall power conversion efficiency (PCE) was 3.1%. In contrast, PM6:PNDIS blends combine a high Voc (0.967 V) with a high fill factor (FF = 0.70) to produce efficient all-PSCs with 9.1% PCE. Furthermore, the high performance PM6:PNDIS all-PSCs could be fabricated by various solution processing approaches and at active layer thickness as high as 300 nm without compromising photovoltaic efficiency. The divergent photovoltaic properties of PNDIS and PNDIBS when paired respectively with PM6 are shown to originate from the starkly different blend morphology and blend photophysics. Efficient PM6:PNDIS blend films were found to exhibit a vertical phase stratification along with lateral phase separation while the molecular packing had a predominant face-on orientation. Bulk lateral phase separation with both face-on and edge-on molecular orientations featured in the poor performing PM6:PNDIBS blend films. Enhanced charge photogeneration and suppressed geminate and bimolecular recombinations with 99% charge collection probability found in PM6:PNDIS blends strongly differ from the poor charge collection probability (66%) and high electron-hole pair recombination seen in PM6:PNDIBS. Our findings demonstrate that beyond the generally expected enhancement of Voc, a fluorinated polymer component in all-PSCs can also exert a positive or negative influence on photovoltaic performance via the blend morphology and blend photophysics.
关键词： Naphthalene Diimide-Arylene Copolymer,Fluorinated donor polymer,Vertical phase stratification,All-polymer solar cells,Thick-film active layer,Blend Morphology
更新于2025-09-23 15:19:57
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Morphological evolution of Co phosphate and its electrochemical and photocatalytic performance
摘要： Three novel 3D calcium-based metal–organic frameworks (FJU-67, FJU-68, and FJU-69) established on naphthalene diimide chromophores have been synthesized, which exhibit unique multiple interpenetrated networks with dia net topologies. It is noticeable that the shape and size of the second carboxylic ligands can directly influence the mode of the interpenetrated frameworks. Linear dicarboxylic acid H2BDC or NH2-H2BDC ligands can yield 5-fold interpenetrated frameworks, while 2,6-naphthalenedicarboxylic acid (H2NDC) ligand with a longer length and slight angle can produce a 4-fold (2 + 2) framework. Among the three Cd-MOFs, FJU-67 and FJU-69 with a relatively pale color exhibit reversible photochromism via the radical formation of NDI units and interpenetrating packing has a definite impact on their photochromic behaviors.
关键词： photochromic,Cd-MOFs,interpenetrated frameworks,naphthalene diimide,second dicarboxylic acid ligands
更新于2025-09-19 17:15:36
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Naphthalene Diimide-Based Terpolymers with Controlled Crystalline Properties for Producing High Electron Mobility and Optimal Blend Morphology in All-Polymer Solar Cells
摘要： We report a series of new n-type random copolymers (P(NDI2OD-Se-Th x) where x = 0, 0.5, 0.7, 0.8, 0.9, 1.0) consisting of naphthalene diimide (NDI), selenophene-2,2’-thiophene (Se-Th), and seleno[3,2-b]thiophene (SeTh) to demonstrate their use in producing efficient all-polymer solar cells (all-PSCs) and organic field-effect transistors (OFETs). To investigate the effect of polymer crystallinity on the performance of all-PSCs and OFETs, we tuned the composition of the Se-Th and SeTh moieties in the P(NDI2OD-Se-Th x) polymers, resulting in enhanced crystalline properties with higher Se-Th ratio. Thus, the OFET electron mobility was increased with higher Se-Th ratio, exhibiting the highest value of 1.38×10?1 cm2 V?1 s?1 with P(NDI2OD-Se-Th 1.0). However, the performance of all-PSCs based on PBDB-T:P(NDI2OD-Se-Th x) showed a non-linear trend relative to the Se-Th ratio and the performance was optimized with P(NDI2OD-Se-Th 0.8) exhibiting the highest power coversion efficiency of 8.30%. This is attributed to the stronger crystallization-driven phase separation in all-polymer blends for higher Se-Th ratio. At the optimal crystallinity of P(NDI2OD-Se-Th 0.8) in all-PSCs, the degree of phase separation, domain purity and the electron mobility were optimized, resulting in enhanced charge generation and transport. Our works describe structure-property-performance relationships to design effective n-type polymers in terms of crystalline and electrical properties suitable for both efficient OFETs and all-PSCs.
关键词： organic field-effect transistors,seleno[3,2-b]thiophene,polymer crystallinity,n-type random copolymers,selenophene-2,2’-thiophene,charge generation,all-polymer solar cells,charge transport,naphthalene diimide
更新于2025-09-19 17:13:59
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Exploring a fused 2-(thiophen-2-yl)thieno[3,2-b]thiophene (T-TT) building block to construct n-type polymer toward high performance all-polymer solar cells
摘要： In the field of all-polymer solar cells (all-PSCs), exploring new electron-donating units (D) to match with electron-accepting units (A) is an important subject to promote the performance of D-A type polymer acceptors. Herein, we developed a fused D unit 2-(thiophen-2-yl)thieno[3,2-b]thiophene (T-TT) derivated from the famous 2-(2-(thiophen-2-yl)vinyl)thiophene (TVT) unit. With classical naphthalene diimide (NDI) as A unit, the new D-A polymer PNDI-T-TT exhibits enhanced absorption coefficient, electron mobility and miscibility with donor polymer in comparison with the analogous PNDI-TVT polymer. These advantages can be attributed to the enlarged conjugation and reduced rotamers due to the fused T-TT unit, leading to stronger intermolecular interaction. When blending with the donor polymer PBDB-T, both NDI-based polymers can form better interpenetrating nanostructures than the corresponding blend films with donor polymer J71. Finally, PBDB-T:PNDI-T-TT device obtains a power conversion efficiency (PCE) of 6.1%, which is much higher than that of PBDB-T:PNDI-TVT device (4.24%). These results demonstrate that n-type polymer based on fused T-TT unit can ameliorate the absorption coefficient, molecular aggregation and charge carrier mobility and consequently achieve improved photovoltaic performance in comparison with classic TVT unit.
关键词： All-polymer solar cells,2-(2-(thiophen-2-yl)vinyl)thiophene,PBDB-T,naphthalene diimide,photovoltaic
更新于2025-09-19 17:13:59
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Positional Isomerism Controlled Electronic and Photochromic Properties of Naphthalene Diimide-Based Chlorozincate Hybrids
摘要： Two organic-inorganic hybrids, [3-H2DPNDI][ZnCl4]·0.5H2O (1) and [4-H2DPNDI][ZnCl4]·0.5H2O (2) (3-H2DPNDI2+ = protonated N, N-di(3-pyridyl)-1,4,5,8-naphthalene diimide, 4-H2DPNDI2+ = protonated N, N-di(4-pyridyl)-1,4,5,8-naphthalene diimide), have been designed and prepared. Compounds 1 and 2 are constructed from typical [ZnCl4]2- inorganic clusters and positional isomeric organic cations of [H2DPNDI]2+, which are assembled into different 3-D supramolecular networks via different anion-π interactions and hydrogen-bonding interactions. Photochromism of 1 and non-photochromism of 2 are attributable to the usage of positional isomers, which lead to the different spatial stack of [ZnCl4]2- donors and [H2DPNDI]2+ acceptors, suggesting delicate modulating effect of the distinct interfacial contacts on the intermolecular charge transfer/electron transfer and consequently photoresponsive behaviors.
关键词： organic-inorganic hybrids,positional isomerism,anion-π interactions,chlorozincate,photochromism,naphthalene diimide
更新于2025-09-16 10:30:52
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Molecular aggregation of Naphthalene diimide(NDI) derivatives in electron transport layers of inverted perovskite solar cells and their influence on the device performance
摘要： One of key factors to design applicable electron transport layers (ETLs) for perovskite solar cells is the morphology of ETLs since a good morphology would help to facilitate the carrier transport at two interfaces (perovskite\ETL and ETL\cathode). However, one drawback of most organic ETL small molecules is the internal undesired accumulation, which would cause the formation of inappropriate morphology and rough ETL surface. Here by elaborately designing the side chains of NDI derivatives, the molecular interaction could be modified to achieve the aggregation in different degrees, which would eventually affect the accumulation of molecules and surface qualities of ETLs. By speculating from the comparison between the absorption spectra of solutions and films, the sequence of extent of molecule interaction and aggregation was built among three NDI derivatives, which is further confirmed by direct evidence of atomic force microscopy (AFM) images. Then, carrier exaction abilities are simply studied by steady state photoluminescence spectra. Carrier transport process is also discussed based on cyclic voltammetry, time-resolved photoluminescence spectra and mobility. NDIF1 are proven to have the appropriate internal aggregation to smooth the contact with cathode and low series resistance, the device performance (15.6%) is achieved. With the ability of preventing the thermal diffusion of Ag towards the perovskite surface due to the strong interaction between molecules, NDIF2 under high concentration shows the highest fill factor (80%).
关键词： solar cell,perovskite,Naphthalene diimide derivatives,molecular aggregation
更新于2025-09-16 10:30:52
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Importance of Device Structure and Interlayer Design in Storage Stability of Naphthalene Diimide-based All-Polymer Solar Cells
摘要： While excellent thermal and mechanical stabilities of all-polymer solar cells (all-PSC) have been demonstrated, the storage stability of all-PSCs has rarely been studied. In this paper, the storage stability of all-PSCs is systematically investigated and compared to fullerene-based polymer solar cells (PCBM-PSCs). We identify that the efficient inverted type all-PSCs made with a molybdenum oxide (MoO3) anode interfacial layer can exhibit degradation over short periods of storage even under inert nitrogen-filled and dark conditions, while the control inverted PCBM-PSCs containing the same polymer donor (PDs) are relatively more stable. To elucidate the origin of the poor storage stability, morphological and electrical properties of all-PSCs are investigated. We reveal that the work function of MoO3 is largely changed during the storage because of the interaction between MoO3 and the underneath naphthalene dimide (NDI)-based PAs. This causes unfavorable energy-level alignment in devices, resulting in increased charge recombination and deteriorated charge collecting efficiency. To resolve this issue, we propose two effective strategies: i) introducing a passivation layer to physically separate the NDI-based PAs and MoO3, and ii) replacing MoO3 with an efficient polymer interlayer. We prove that the modified all-PSCs not only exhibit the excellent storage stability with high power conversion efficiency for more than 45 days, but also show high air-stability even without encapsulation. Our findings provide better understanding of the storage stability of all-PSCs and suggest future guidelines for efficient and burn-in free all-PSCs.
关键词： stability,burn-in degradation,all-polymer solar cells,storage lifetime,interlayers,naphthalene diimide polymers
更新于2025-09-16 10:30:52
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Fine-Tuning Semiconducting Polymer Self-Aggregation and Crystallinity Enables Optimal Morphology and High-Performance Printed All-Polymer Solar Cells
摘要： Polymer aggregation and crystallization behavior play a crucial role in the performance of all-polymer solar cells (all-PSCs). Gaining control over polymer self-assembly via molecular design to influence bulk-heterojunction active-layer morphology, however, remains challenging. Herein, we show a simple yet effective way to modulate the self-aggregation of the commonly used naphthalene diimide (NDI)-based acceptor polymer (N2200), by systematically replacing a certain amount of alkyl side-chains with compact bulky side-chains (CBS). Specifically, we have synthesized a series of random co-polymer (PNDI-CBSx) with different molar fractions (x = 0–1) of the CBS units and have found that both solution-phase aggregation and solid-state crystallinity of these acceptor polymers are progressively suppressed with increasing x as evidenced by UV-Vis absorption, photoluminescence (PL) spectroscopies, thermal analysis and grazing incidence X-ray scattering (GIWAXS) techniques. Importantly, compared to the highly self-aggregating N2200, photovoltaic results show that blending of more amorphous acceptor polymers with donor polymer (PBDB-T) can enable all-PSCs with significantly increased PCE (up to 8.5%). The higher short-circuit current density (Jsc) results from the smaller polymer phase-separation domain sizes as evidenced by PL quenching and resonant soft X-ray scattering (R-SoXS) analyses. Additionally, we show that the lower crystallinity of the active layer is less sensitive to the film deposition methods. Thus, the transition from spin-coating to solution coating can be easily achieved with no performance losses. On the other hand, decreasing aggregation and crystallinity of the acceptor polymer too much, reduces the photovoltaic performance as the donor phase-separation domain sizes increases. The highly amorphous acceptor polymers appear to induce formation of larger donor polymer crystallites. These results highlight the importance of a balanced aggregation strength between the donor and acceptor polymers to achieve high-performance all-PSCs with optimal active layer film-morphology.
关键词： morphology control,crystallinity,polymer aggregation,naphthalene diimide,all-polymer solar cells
更新于2025-09-11 14:15:04