Towards Single-component Molecular Conductor[Ni(dmit)2]by Charge Disproportionation:2[Ni(dmit)2]^0.5→[Ni(dmit)2]+[Ni(dmit)2]^-

A new method of synthesizing single-component molecular conductor [Ni(dmit)2] by the reaction 2(Me4N)[Ni(dmit)2]2 [Ni(dmit)2] + (Me4N)[Ni(dmit)2] is reported. [Ni(dmit)2] exhibits a semiconductive behavior above 167 K, while from 167 K down to the measuring limit of 60 K, it exhibits metallic conductivity.

Alkyl-thiophene-alkyl linkers to construct double-cable conjugated polymers for single-component organic solar cells

In this work,semirigid linkers of the alkyl-thiophene-alkyl structure are developed to construct double-cable polymers.Three alkyl units,propyl(C3H6),hexyl(C6H12),and dodecyl(C12H24),are applied as semirigid linkers,yielding three double-cable polymers:PBC6-T,PBC12-T,and PBC24-T,respectively.PBC12-T which uses C6H12-thiophene-C6H12 linkers is found to exhibit the best device efficiency of 5.56%,while PBC6-T and PBC24-T with shorter or longer linkers yield device efficiencies of only 2.65%and 1.09%in single-component organic solar cells(SCOSCs).Further studies reveal that PBC12-T exhibits higher crystallinity and improved charge transport,resulting in better efficiencies.Our work provides an approach to construct double-cable conjugated polymers with long alkyl linkers,and it shows the importance of the linker length for the photovoltaic performance of SCOSCs.

Near-infrared double-cable conjugated polymers based on alkyl linkers with tunable length for single-component organic solar cells

The photovoltaic properties of double-cable conjugated polymers are significantly influenced by the length of the alkyl linkers that connect donor backbones and acceptor side units. In this study, a series of 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile(IC)-based double-cable polymers with alkyl linkers ranging from C_8H_(16)to C_(16)H_(32)(Px, x = 8, 10, 12, 14, 16) were synthesized for single-component organic solar cells(SCOSCs). Among these, the linker length x = 12(P12) is found to optimize the power conversion efficiencies(PCEs) in SCOSCs. Specifically, PCEs increase from P8 to P12 and then decline from P12to P16. Detailed investigations of optical absorption, charge transport, and morphology provide insights into the underlying factors contributing to these PCE variations. The findings indicate that the exceptional photovoltaic properties observed in P12 can be attributed to three key factors: A delicate balance between enhanced charge separation facilitated by the increased spacer length and reduced crystallinity resulting from longer spacers, higher charge mobilities, and well-balanced hole/electron transport characteristics. This study highlights the critical role of linker length in determining the photovoltaic properties of double-cable conjugated polymer-based SCOSCs and offers valuable guidance for the design of novel double-cable conjugated polymers.

Fused-ring induced end-on orientation in conjugated molecular dyads toward efficient single-component organic solar cells

The molecular orientations of conjugated materials on the substrate mainly include edge-on,face-on,and end-on.Edge-on and face-on orientations have been widely observed,while end-on orientation has been rarely reported.Since in organic solar cells(OSCs)charge transport is along the vertical direction,end-on orientation with conjugated backbones perpendicular to the substrate is recognized as the ideal microstructure for OSCs.In this work,we for the first time obtained the preferential end-on orientation in a conjugated molecular dyad that contains a conjugated backbone as donor and perylene bisimide side units as acceptor.This was realized by introducing a fused-ring structure to replace linear terthiophenes with conjugated backbones,yielding F-MDPBI and L-MDPBI respectively.Surprisingly,a shifting trend of the molecular orientation from dominating edge-on in L-MDPBI to preferential end-on in F-MDPBI was observed.As a consequence,vertical charge carrier mobilities in F-MDPBI are one order of magnitude higher than those with preferential edge-on orientation,so single-component OSCs based on this molecular dyad as a single photoactive layer provided a power conversion efficiency of 4.89% compared to 1.70% based on L-MDPBI with preferential edge-on orientation.

Dual-Emission Carbonized Polymer Dots Combined with Metal Ions as a Single-Component Fluorescence Sensor Array for Pattern Recognition of Glycosaminoglycans

Herein,a novel dual-emission fluorescence sensor array of carbonized polymer dots(CPDs)-Cu^(2+)has been proposed,in which CPDs were prepared by one-pot hydrothermal method and Cu^(2+)acting as a quencher was combined with CPDs by electrostatic interaction.Four negatively charged glycosaminoglycans(GAGs)bearing different hydrophilic groups showed variable binding affinities towards CPDs-Cu^(2+).Upon reacting with these GAGs,the different fluorescence response signals of CPDs-Cu^(2+)can be further differentiated by principal component analysis(PCA).The CPDs-Cu^(2+)sensor array,not only allows the identification of four similarly structured GAGs,but also realizes the discrimination of different concentrations of the same GAGs and their mixtures.Remarkably,the identification of GAGs in biological fluids can also be achieved using our proposed single-component sensor array,validating its application potential.This new strategy avoids multiple sensing probes,broadens the application of tongue-mimic sensor arrays and provides a viable idea for the development of single component sensing platforms.

Chlorinated Effects of Double-Cable Conjugated Polymers on the Photovoltaic Performance in Single-Component Organic Solar Cells

The recently emerged double-cable conjugated polymers have come into focus due to their significantly improved power conversion efficiencies (PCEs) in single-component organic solar cells (SCOSCs). In this work, the effect of chlorination in double-cable conjugated polymers with linear benzodithiophene backbone and pendant perylene bisimide on the photovoltaic performance in SCOSCs has been studied. After introducing chlorine atoms into conjugated side chains, the highest occupied molecular orbital level of the conjugated polymers is down-shifted, thus resulting in a higher open-circuit voltage. As a result, the chlorinated double-cable conjugated polymer exhibits improved photovoltaic performance from 3.46% to 3.57%.

Achieving white-light emission in a single-component polymer with halogen-assisted interaction

White-light emitting(WLE) polymers have attracted continuous attention for their promising applications in solid-state lighting,flexible display and related fields. However, achieving dual-emission and pure white-light emission in a single-component polymer is still challenging. In this study, a brominated single-component polymer Br OD-TFB was designed and synthesized,which shows dual-emission and white light emission properties in solution and room-temperature phosphorescence(RTP) in thin films. The dual-emission properties can be tuned by concentration, solvent polarity, and excitation energy. Spectral analyses and theoretical calculations reveal that the origin of the high-energy emission band(HEB) is intramolecular charge transfer(ICT)along the polymer chain, whilst the low-energy emission band(LEB) originates from the excited-state related to the intra-chain and inter-chain C–Br···π interactions as demonstrated by the single-crystal structure of the model compound. Appropriate control of the formation and the destruction of the halogen-assisted interactions can initiate white-light emission in the singlecomponent polymer. More interestingly, by dispersing Br OD-TFB(0.1 wt%) in a non-emissive, colorless and transparent polymer, the characteristics of this white-light emission can be fully demonstrated while exhibiting unexpected RTP properties,with photoluminescence quantum efficiency(Φ_(PL)) of up to 23% and CIE coordinates of(0.32, 0.32).

A benzo[ghi]-perylene triimide based double-cable conjugated polymer for single-component organic solar cells

Single-component organic solar cells(SCOSCs)with high stability and simplified fabrication process are supposed to accelerate the commercialization of organic photovoltaics.However,the types of photo-active materials and photovoltaic performance of SCOSCs are still far lagging behind the bulk-heterojunction type organic solar cells(BHJ OSCs).It is still an arduous task to introduce new photo-active materials into SCOSCs,aiming to improve the efficiencies of SCOSCs.One feasible way is to construct double-cable polymers with new structures and tune conformation,morphology and mobility for the improvement in power conversion efficiencies(PCEs).Hence,in this work,we constructed a new double-cable polymer PBTT-BPTI by introducing fused core 5,7-dibromo-2,3-bis(2-ethylhexyl)benzo[1,2-b:4,5-c’]dithiophene-4,8-dione(TTDO)into the main backbone and benzo[ghi]-perylene triimide(BPTI)unit into the side chain.Both of the two units show strong electron-withdrawing property,which are expected to broaden absorption spectra and enhance intermolecular interaction.The double-cable polymer exhibited a broad absorption in the range of 300-700 nm with an optical band gap(E_(g))of 1.79 eV.The PCE of PBTT-BPTI-based SCOSCs was 2.15%,which may be limited by the unconstructed efficient electron transporting channels.

Double-Cable Conjugated Polymers with Fullerene Pendant for Single-Component Organic Solar Cells

In this work,the“functionalization-polymerization”(FP)method has been used to construct fullerene-contained double-cable conjugated polymers with“donor-acceptor”backbones.It was realized via synthesizing a fullerene-contained monomer and performing Stille polymerization.With this method,a series of double-cable conjugated polymers with different fullerene contents were developed and applied into single-component organic solar cells.The power conversion efficiencies(PCEs)based on these polymers increased from 0.71%to 1.71%with the enhanced fullerene contents.The relatively low PCEs might be originated from the poor microstructure in these polymers.These new conjugated polymers with molecular heterojunction would show potential application in organic electronic devices.

Metallophilicity-Induced Clusterization:Single-Component White-Light Clusteroluminescence with Stimulus Response

Materials showing metallophilic interactions continue to attract considerable theoretical and experimental attention largely because of their unusual and unanticipated photophysical behavior as well as their unique stimuli-responsive behavior in an aggregate or solid state.Metallophilic interactions are mostly found between metals with either identical(d^(10)–d^(10))or different(s^(2)–d^(8),d^(8)–d^(10))configurations.Among various metallophilic interactions,aurophilic interactions(Au⋯Au)are well-known and widely reported.In this study,a new phosphorescent gold(I)complex,[(CF_(3)Ph)_(3)PAuC≡CPh](TPPGPA)was reported.

Chemical synthesis of magnetic nanocrystals:Recent progress

Colloidal chemical synthesis of various types of magnetic nanocrystals is discussed with regard to recent discoveries. We first outline the chemical preparation of single-component magnetic nanocrystals with controlled size, shape, and uniformity based on several solution-phase methods, especially thermal decomposition and/or reduction method. Then we discuss the synthetic strategies of multi-component nanocrystals incorporating at least one magnetic component by manipulating heterogeneous nucleation and growth process. Toward the end, approaches for preparing hollow/porous magnetic nanocrystals are highlighted. We believe that the summarized chemical synthesis will pave the way for the future development of extraordinary magnetic nanocrystals.

Understanding the Impact of Fluorine Substitution on the Photovoltaic Performance of Block Copolymers

Fluorine substitution was applied to the donor and acceptor segments of block copolymers to understand the impact of molecular structure on photovoltaic block copolymers and explore efficient materials for single-component organic solar cells(SCOSCs).Along this line,three fluorinated block copolymers,namely PBDB-T-b-PTYF6,PM6-b-PTY6,and PM6-bPTYF6,derived from PBDB-T-b-PTY6 were designed and synthesized.The UV-Vis absorption,energy level,and thin-film morphology of these block copolymers were systematically characterized.All fluorinated block copolymers show narrow bandgap and improved crystallinity.An enhanced open-circuit voltage was observed in the SCOSC based on PM6-b-PTY6.However,SCOSCs based on all fluorinated block copolymers exhibited low short-circuit current due to energy level mismatch and therefore had low power conversion efficiency at around 4%.By contrast,the SCOSCs based on control block copolymer PBDB-T-b-PTY6 exhibited the highest power conversion efficiency approaching 10%,with a high short-circuit current of 18.57 mA/cm~2.Our study was the first to perform fluorination on photovoltaic block copolymers and provides insight into precisely controlling the polymer structure and understanding the structure-property relationship in SCOSCs based on block copolymers.

Hydrothermal synthesis of uniform CdWO4:Eu^3+microrods as single component for UV-based WLEDs

A series of single-composition emission-tunable CdWO4：Eu^3＋ uniform size nanorods were synthesized by polyvinylpyrrolidone（PVP） assisted hydrothermal process. The products were measured by powder X-ray diffraction（PXRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, photoluminescence, and fluorescent decay test. The results showed that reaction time, temperature, p H values and Eu^3＋ doped concentration played important roles in determining the morphologies and photoluminescent properties. And we also investigated its use in Ga N LED, warm-white-light could be obtained by the combination of the bright blue light originated from the charge transfer transition in the tungstate groups and the near UV light from LED chip with the red emission from 4f-4f transition of Eu^3＋, respectively. By properly tuning the doping concentration of Eu^3＋, chromaticity coordinates（0.30 0.22） could be achieved under the 380 nm excitation and its color rendering index was 80.6. So it has potential application in warm-WLED and replacing the commercial YAG：Ce phosphor which absence of red band emission.

Alternating copolymerization of CO_(2) and cyclohexene oxide initiated by rare-earth metal complexes stabilized by o-phenylenediamine-bridged tris(phenolate)ligand

A series of o-phenylenediamine bridged tris(phenolate)ligand-stabilized rare-earth metal complexes were synthesized and characterized.Lanthanum(complex 1),neodymium(complex 2^(tBu)),and yttrium(complex 3)complexes stabilized by ligand of buiky tert-butyl substituents are mononuclear,whereas neodymium complexes 2^(Me)and 2^(C1)bearing smaller methyl and chloro substituents are dinuclear,respectively.They were applied in the alternating copolymerization of CO_(2)and cyclohexene oxide.The addition of benzyl alcohol is beneficial to improving yields(up to 86%)and selectivity of poly(carbonate)(up to 99%).Stoichiometric reaction of benzyl alcohol with rare-earth metal complexes 1 and 2^(tBu)results in formation of complexes 4 and 5 as dinuclear complexes with benzyl alcohol coordination,which was confirmed via single crystal X-ray diffraction analysis,and nuclear magnetic resonance(NMR)spectroscopy(for 4).Complex 5 shows equally good activity and selectivity of that of complex 2^(tBu)and benzyl alcohol,consolidating that complex 5 is indeed generated during polymerization.The neodymium tris(phenolate)5 is one of the few examples of rare-earth metal complex as a single-component initiator for copolymerization of epoxide and CO_(2).Matrix-assisted laser desorption ionization-time of flight(MALDI-TOF)mass spectrometry analysis proves benzyloxy group as the chain end.^(1)H NMR monitoring suggests that the insertion of CO_(2)may be the first step in the growth of the polymer chain.

An Isoindigo-Based ＂Double-Cable＂ Conjugated Polymer for SingleComponent Polymer Solar Cells

An isoindigo-based ＂double-cable＂ conjugated polymer bearing perylene bisimide side units was developed via Stille polymerization for application in single-component polymer solar cells, in which a power conversion efficiency of 1% with broad photo-response from 300 nm to 800 nm was achieved. There is no evidence of large phase separation confirmed by AFM images and photoluminescence （PL） spectra. The space charge limit current measurements and light intensity dependence measurements indicate that the low electron mobility and the significant recombination of pho- togenerated charge carriers in active layer mainly account for the low performance of our solar cells. Our results suggest that these ＂double-cable＂ are oromising candidates for use in single-component polymer solar cells with NIR photoresponse.