Co-reporter:Congyuan Wei, Jiabin Zou, Rui Zhu, Jianyao Huang, Dong Gao, Liping Wang, Weifeng Zhang, Yi Liao, Gui Yu
Dyes and Pigments 2017 Volume 136() pp:434-440
Publication Date(Web):January 2017
DOI:10.1016/j.dyepig.2016.09.005
•Acceptor-donor-acceptor type small molecules based on indolone were synthetized and characterized.•The field-effect transistors were fabricated and the high mobility of 0.10 cm2 V−1 s−1 was obtained.•Halide effect was investigated by introducing fluorine and chlorine atoms in the five position of indolone.In this paper we present the design and synthesis of three π-extended indolone derivatives, namely (3Z,3′Z)-3,3′-((5,5′-((E)-ethene-1,2-diyl)bis(thiophene-2,5-diyl))bis(methanylylidene))bis(1-octylindolin-2-one) (3a), (3Z,3′Z)-3,3′-((5,5′-((E)-ethene-1,2-diyl)bis(thiophene-2,5-diyl))bis(methanylylidene))bis(5-fluoro-1-octylindolin-2-one) (3b) and (3Z,3′Z)-3,3′-((5,5′-((E)-ethene-1,2-diyl)bis(thiophene-2,5-diyl))bis(methanylylidene))bis(5-chloro-1-octylindolin-2-one (3c), with (E)-1,2-di(thiophen-2-yl)ethene as the donor and indolin-2-ones as the acceptors. All of the three acceptor-donor-acceptor type molecules have high conjugations and planar energy-minimized conformations, which are beneficial to forming ordered molecular packing and facilitating charge transport in thin films. Additionally, to study the effect of halogenation, fluorine and chlorine atoms were introduced in terms of microscale and mesoscale molecular engineering. 3b and 3c show obviously different features of crystalline tendencies and morphologies compared with those of 3a. Organic field-effect transistors based on the three small molecules display typical p-channel charge transport characteristics under ambient conditions. Fluorinated 3b affords the highest mobility of 0.1 cm2 V−1 s−1 among the three analogues, demonstrating that fluorination is a useful strategy to optimize the solid-state arrangement and device performances.
Co-reporter:Weifeng Zhang, Keli Shi, Congyuan Wei, Yankai Zhou, Liping Wang, Gui Yu
Polymer 2017 Volume 132(Volume 132) pp:
Publication Date(Web):6 December 2017
DOI:10.1016/j.polymer.2017.10.055
•Four novel flurionated copolymers, PTIDTE, PTIFDTE, PTIDFPE, PTITFPE, were developed.•PTIDTE/PTIDFPE exhibited p-type transport properties, whereas PTIFDTE/PTITFPE afforded ambipolar transport properties.•Backbone fluorination is an effective approach to tuning the carrier transport properties of polymer semiconductors.Herein, we demonstrate an effective fine-tuning of carrier transport properties in polymer semiconductors by loading fluorine atoms on polymeric π-systems. To a thienoisoindigo-based conjugated backbones, we introduced dithiophenethene, difluorodithiophenethene, difluorodiphenylethene, and tetrafluorodiphenylethene units affording D−A copolymers, PTIDTE, PTIFDTE, PTIDFPE, and PTITFPE, respectively. PTIDTE and PTIDFPE exhibited unipolar p-channel transport properties with mobilities of 0.24 and 0.11 cm2 V−1 s−1, respectively, whereas PTIFDTE and PTITFPE afforded ambipolar transport properties with the highest hole/electron mobilities of 0.072/0.017 cm2 V−1 s−1 and 0.017/0.0034 cm2 V−1 s−1, respectively. Thin film microstructure studies (AFM and 2D-GIXRD) suggest that more ordered lamellar and predominantly edge-on molecular packing mode formed in the PTIFDTE and PTITFPE thin films though they own inferior surface morphologies. The thienoisoindigo-based polymers' backbone conformations were purposed to interpret their different molecular packing mode in solid state, revealing that single conjugated backbone conformations are much easier to form for PTIFDTE and PTITFPE.Download high-res image (166KB)Download full-size image
Co-reporter:Liping Wang, Fu Zhang
Ceramics International 2017 Volume 43, Issue 13(Volume 43, Issue 13) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.ceramint.2017.04.147
Indium tin oxide (ITO) nanoparticles and gallium-doped indium tin oxide (GITO) nanoparticles with various molar ratios of dopants were prepared by a solution method in oleylamine. Characterization of crystal, morphology, and optical properties was carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet–visible (UV–Vis), photoluminescent (PL), and Fourier transform infrared spectroscopy (FT-IR). XRD patterns show that with increasing of Sn, the crystal structure of ITO nanoparticles varies gradually from standard cubic bixbyite In2O3 to amorphous and to standard tetragonal SnO2, whereas the GITO nanoparticles retain the crystal structure of ITO. The smallest particle size is around 10 nm, and the morphology of the particles is nearly spherical. The smallest particles, though coated with oleylamine, tend to aggregate forming larger flower-like particles. Defect level emission at the present of dopants was observed in the PL spectra of the ITO and GITO nanoparticles.
Co-reporter:Congyuan Wei;Jiabin Zou;Weifeng Zhang;Jianyao Huang;Dong Gao;Yi Liao;Gui Yu
Materials Chemistry Frontiers 2017 vol. 1(Issue 10) pp:2103-2110
Publication Date(Web):2017/09/27
DOI:10.1039/C7QM00236J
Two novel vinylene-bridged π-extended building blocks, (2E,2′E)-3,3′-(2,5-bis(octyloxy)-1,4-phenylene)bis(2-(5-bromothiophen-2-yl)acrylonitrile) (BOPACN) and 5,5′-((1E,1′E)-(2,5-bis(octyloxy)-1,4-phenylene)bis(ethene-1,2-diyl))bis(2-bromothiophene) (BOPA), were synthesized. They were further copolymerized with two diketopyrrolopyrrole (DPP) units possessing different alkyl side chains, and four donor–acceptor copolymers, namely PBOPACN-1, PBOPACN-2, PBOPA-1 and PBOPA-2, were synthesized. The optical, thermal, and electrochemical properties and field-effect properties of all copolymers were systematically investigated by theoretical calculations and experimental methods. Field-effect transistors based on these copolymers exhibited p-type charge transport characteristics in air. The performance implies that cyano substituents exert an important influence on semiconducting behaviours. Furthermore, 2D-GIXRD and theoretical calculations demonstrate that the presence of cyano substituents improves molecular planarity and generates highly-ordered molecular aggregates for PBOPACN-1 and PBOPACN-2.
Co-reporter:Weifeng Zhang;Zupan Mao;Zhihui Chen;Jianyao Huang;Congyuan Wei;Dong Gao;Zuzhang Lin;Hao Li;Gui Yu
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 5) pp:879-889
Publication Date(Web):2017/01/31
DOI:10.1039/C6PY01922F
Herein, we present three kinds of tetrafluorodiphenylethene (TFPE)-based building blocks with multiple F⋯H–C and F⋯S conformational locks. Based on this, three copolymers PD23TFPE, PD26TFPE, and PD25TFPE were developed. Field-effect transistors based on these copolymers all exhibited ambipolar carrier transport characteristics, and the highest hole/electron mobilities were achieved in the PD25TFPE-based device. Thin film microstructure analyses suggest that PD25TFPE forms a highly ordered and dense thin film with an edge-on lamellar molecular packing. The crystallographic data of TFPE-based small molecules indicate that PD25TFPE assumes a linearly, fully “locked” conjugated backbone conformation, whereas PD23TFPE and PD26TFPE have a bent, fully “locked” or a linearly, partly “locked” conjugated backbone conformation. Our studies reveal the important influence of multiple conformation locks on tuning the backbone conformation, molecular packing mode in the solid state, and thus on the charge transport properties of polymer semiconductors.
Co-reporter:Li-ping Wang;Fu Zhang;Shuai Chen
International Journal of Minerals, Metallurgy, and Materials 2017 Volume 24( Issue 4) pp:455-461
Publication Date(Web):2017 April
DOI:10.1007/s12613-017-1426-1
Colloidal indium-doped zinc oxide (IZO) and tin-doped zinc oxide (ZTO) nanoparticles were successfully prepared in organic solution, with metal acetylacetonate as the precursor and oleylamine as the solvent. The crystal and optical properties were characterized by X-ray diffraction, UV−visible spectrophotometry, and fluorescence spectroscopy, respectively; the surface and structure morphologies were observed by scanning electron microscopy and transmission electron microscopy. The XRD patterns of the IZO and ZTO nanoparticles all exhibited similar diffraction peaks consistent with the standard XRD pattern of ZnO, although the diffraction peaks of the IZO and ZTO nanoparticles were slightly shifted with increasing dopant concentration. With increasing dopant concentration, the fluorescent emission peaks of the IZO nanoparticles exhibited an obvious red shift because of the difference in atomic radii of indium and zinc, whereas those of the ZTO nanoparticles exhibited almost no shift because of the similarity in atomic radii of tin and zinc. Furthermore, the sizes of the IZO and ZTO nanoparticles distributed in the ranges 20–40 and 20–25 nm, respectively, which is attributed to the difference in ionic radii of indium and tin.
Co-reporter:Liping Wang;Limin Wang;Jianyao Huang;Gui Yu
Chinese Journal of Chemistry 2015 Volume 33( Issue 8) pp:948-954
Publication Date(Web):
DOI:10.1002/cjoc.201500322
Abstract
Three novel dibenzo[a,d]cyclohepten-5-one derivatives containing hole-transporting groups were synthesized and characterized. These compounds exhibit good thermal stabilities. Single crystals of DBHO-TPA and DBHO-DPA were successfully grown from dichloromethane and their crystal structures were determined from X-ray diffraction data. Two molecules, DBHO-TPA and DBHO-DPA, have a nonplanar structure while seven-membered ring comprised in dibenzo[a,d]cyclohepten-5-one is not planar. Electrochemical properties of three compounds indicate that the different substituents on 3,7-positions of the dibenzo[a,d]cyclohepten-5-one derivatives have a small effect on the energy levels of the highest occupied molecular orbitals. The blue-green light-emitting diodes based on dibenzo[a,d]cyclohepten-5-one derivatives were fabricated.
Co-reporter:Li-ping Wang;Xu-dong Xu;Jia-xing Wang
International Journal of Minerals, Metallurgy, and Materials 2015 Volume 22( Issue 5) pp:543-548
Publication Date(Web):2015 May
DOI:10.1007/s12613-015-1105-z
Oil-soluble In2O3 nanoparticles and In2O3–SnO2 nanocomposites were prepared in oleylamine via decomposition of metal acetylacetonate precursors. Thin films of In2O3 and In2O3–SnO2 were obtained by spin-coating solutions of the oil-soluble In2O3 nanoparticles and In2O3–SnO2 nanocomposites onto substrates and then calcining them. Transmission electron microspectroscopy, scanning electron microspectroscopy, atomic force microspectroscopy, X-ray diffraction, ultraviolet–visible absorption, and photoluminescence spectroscopy were used to investigate the properties of the nanoparticles and thin films. The In2O3 nanoparticles were cubic-phased spheres with a diameter of ~8 nm; their spectra exhibited a broad emission peak centered at 348 nm. The In2O3–SnO2 nanocomposites were co-particles composed of smaller In2O3 particles and larger SnO2 particles; their spectra exhibited a broad emission peak at 355 nm. After the In2O3–SnO2 nanocomposites were calcined at 400°C, the obtained thin films were highly transparent and conductive, with a thickness of 30–40 nm; the surfaces of the thin films were smooth and crack-free.
Co-reporter:Liping Wang;Yujie Sun
Luminescence 2015 Volume 30( Issue 1) pp:86-90
Publication Date(Web):
DOI:10.1002/bio.2695
Abstract
ZnxCd1-xS/alginate core/shell nanoparticles were synthesized via a colloidal route by reacting zinc and cadmium ions with sulfide ions, followed by coating with alginate. The crystal structure, morphology, size and optical properties of the core/shell nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, UV/vis and photoluminescent spectra, respectively. The ZnxCd1-xS nanoparticles are spherical and have a cubic structure with a mean crystalline size of 2–4 nm. The band gap of ZnxCd1-xS/alginate core/shell nanoparticles increases with increasing Zn/Cd molar ratio, and the UV/vis absorption blue-shifts correspondingly. Two emissions related to zinc and sulfide ion vacancies were observed for the ZnxCd1-xS/alginate core/shell nanoparticles due to the surface changes from the alginate coating. A cadmium-related emission was observed for both the uncovered ZnxCd1-xS and ZnxCd1-xS/alginate core/shell nanoparticles, which has a significant blue-shift with increasing Zn/Cd molar ratio. Copyright © 2014 John Wiley & Sons, Ltd.
Co-reporter:Liping Wang, Xiaodong Xie, Shaowei Shi, Keli Shi, Zupan Mao, Weifeng Zhang, Haiqiao Wang, Gui Yu
Polymer 2015 Volume 68() pp:302-307
Publication Date(Web):26 June 2015
DOI:10.1016/j.polymer.2015.05.033
•(E)-2-(2-(thiophen-2-yl)vinyl)thiophen-based donor–acceptor copolymers were synthesized.•Both polymers exhibit good solubility and solution processability.•Thin-film transistors show hole transporting properties.•The highest hole mobility reaches to 0.5 cm2 V−1 s−1 under ambient conditions.•The annealing treatment has a large effect on the device performance.Two donor–acceptor copolymers, PTVTBT and PTVTBO, using the highly π-extended (E)-2-(2-(thiophen-2-yl)vinyl)thiophen as an electron-rich unit and benzodiathiazole or benzoxadiazole as an electron-deficient one, were designed and synthesized via a Pd-catalyzed Stille-coupling method. The copolymers possess high thermal stability, broad absorption, low band gap, and good film-forming ability. Meanwhile the two polymers exhibit excellent hole transport properties when used as the active layer in polymer field-effect transistor devices. The highest hole mobility can reach to 0.25 and 0.50 cm2 V−1 s−1 for the PTVTBT and PTVTBO thin films, respectively. This work demonstrates that PTVTBT and PTVTBO would be promising semiconductors for developing cost-effective and large-scale production of flexible organic electronics.
Co-reporter:Liping Wang, Xiaodong Xie, Weifeng Zhang, Ji Zhang, Mingshan Zhu, Yunlong Guo, Penglei Chen, Minghua Liu and Gui Yu
Journal of Materials Chemistry A 2014 vol. 2(Issue 32) pp:6484-6490
Publication Date(Web):03 Jul 2014
DOI:10.1039/C4TC00251B
High-performance organic phototransistors (OPTs) have been successfully constructed using bitriisopropylsilylethynyl tetraceno[2,3-b]thiophenes (TIPSEthiotet) or pentacene as a semiconductor layer. Fluorographene (FG) nanosheets were used to modify the interface between an organic semiconductor layer and gate dielectric. The effects of interface modification were investigated. It was found that enhanced photoresponsivity and a boosted photocurrent/dark-current ratio could be easily achieved after the implantation of modification layers. The constructed FG-modified devices based on TIPSEthiotet showed a maximum photoresponsivity of 21.83 A W−1 and a photocurrent/dark-current ratio of 1.85 × 106 under white light irradiation. Meanwhile, for the FG-modified OPT device based on pentacene, a high photoresponsivity of 144 A W−1 was obtained under white light irradiation with an optical power of as low as 25 μW cm−2. This photoresponsivity datum is higher than that of most OPTs based on pentacene reported under the same conditions. In addition, the mobilities of the devices could also be increased distinctly after the introduction of the FG-modified layer. The experimental facts indicate that the strong electron trapping ability of the fluorine atoms in the FG nanosheets and the well-known photovoltaic effect play an important role in these interesting results.
Co-reporter:Liping Wang;Yujie Sun ;Fu Zhang
Polymer Composites 2014 Volume 35( Issue 3) pp:477-481
Publication Date(Web):
DOI:10.1002/pc.22684
Nanocomposite films of CdS:Cu nanoparticles with chitosan and sodium alginate were prepared using spin-coating method, and characterized by X-ray diffraction, transmission electron microscopy, atomic force microscopy (AFM), ultraviolet–visible (UV–vis), and photoluminescent spectrum. The CdS:Cu nanoparticles have a cubic structure with an average crystal size of ∼2 nm, which show blue shift in UV–vis absorption spectra compared to bulk CdS. Furthermore, the CdS:Cu nanoparticles are formed steadily with increasing number of composite layers and homogeneously distributed between the chitosan and alginate layer. AFM measurement shows that the average height of a mono-layered composite film is 25 nm. Emissions ascribed to the electron–hole recombination of CdS and the t2-like energy level of Cu was observed for the multi-layered composite films. POLYM. COMPOS., 35:477–481, 2014. © 2013 Society of Plastics Engineers
Co-reporter:Liping Wang;Yujie Sun ;Xiaodong Xie
Luminescence 2014 Volume 29( Issue 3) pp:288-292
Publication Date(Web):
DOI:10.1002/bio.2542
ABSTRACT
Chitosan/alginate multilayers were fabricated using a spin-coating method, and ZnS:Cu nanoparticles were generated within the network of two natural polysaccharides, chitosan and sodium alginate. The synthesized nanoparticles were characterized using an X-ray diffractometer (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and atomic force microscopy (AFM). The results showed that cubic zinc blende-structured ZnS:Cu nanoparticles with an average crystal size of ~ 3 nm were uniformly distributed. UV–vis spectra indicate a large quantum size effect and the absorption edge for the ZnS:Cu nanoparticles slightly shifted to longer wavelengths with increasing Cu ion concentrations. The photoluminescence of the Cu-doped ZnS nanoparticles reached a maximum at a 1% doping level. The ZnS:Cu nanoparticles form and are distributed uniformly in the composite multilayer films with a surface average height of 25 nm. Copyright © 2013 John Wiley & Sons, Ltd.
Co-reporter:Weifeng Zhang, Ji Zhang, Xiangyang Chen, Zupan Mao, Xiaodong Xie, Liping Wang, Yi Liao, Gui Yu, Yunqi Liu and Daoben Zhu
Journal of Materials Chemistry A 2013 vol. 1(Issue 39) pp:6403-6410
Publication Date(Web):29 Aug 2013
DOI:10.1039/C3TC31421A
In order to study the influence of molecular conformation on the packing mode of single crystals, four bitrialkylsilylethynyl thienoacenes, TIPS–ABT, TMS–ABT, TIPS–CABT and TMS–CABT, were synthesized and characterized. Since there are different conformations arising from the rotation of the isopropyl groups, two types of single crystals of the thienoacene TIPS–ABT were successfully grown, and the related quantum-chemical calculations predict that in theory they have significantly different hole mobilties (μh). For example, the μh of TIPS–ABT-1 is 1.74 cm2 V−1 s−1, a value nearly two hundred times larger than that of TIPS–ABT-2 (0.09 cm2 V−1 s−1), when the reorganization energy is obtained at the B3LYP/6-31+G(d) level. The results demonstrate the important influence of molecular conformation on the mode of crystal packing, and theoretically show the importance of organic semiconductor conformational control on the charge mobility. The thin film FET devices based on the four thienoacenes were prepared via the vacuum-deposit method. The TIPS–CABT-based devices afford hole mobilities of up to 0.012 cm2 V−1 s−1 with a current on–off ratio of 106.
Co-reporter:Minliang Zhu, Hao Luo, Liping Wang, Yunlong Guo, Weifeng Zhang, Yunqi Liu, Gui Yu
Dyes and Pigments 2013 Volume 98(Issue 1) pp:17-24
Publication Date(Web):July 2013
DOI:10.1016/j.dyepig.2013.02.007
2,6-Dialkylphenyldithieno[3,2-b:2′,3′-d]thiophene derivatives (DPCn–DTT) were synthesized and characterized. Effect of alkyl groups on optical characteristics, electrochemical properties, film-forming ability, and field-effect performance was studied. The four compounds DPCn–DTT show almost the same energy levels of the highest occupied molecular orbits and optical energy gaps, but they exhibit different charge carrier transport characteristics. The thin film transistors based on DPC1–DTT with the shortest alkyl groups (methyl groups) show the highest mobility of 0.54 cm2 V−1 s−1. Substrate temperature and surface modification of the SiO2 insulators have a remarkable effect on field-effect performance. High-quality microribbons of DPC8–DTT with octyl groups were prepared by a solution-phase self-assembly process. Single crystal field-effect transistors based on an individual DPC8–DTT microribbon exhibit a high mobility of 1.1 cm2 V−1 s−1 with a current on/off ratio of 6.5 × 104.Graphical abstractHighlights► Dialkylphenyldithieno[3,2-b:2′,3′-d]thiophenes were synthesized as organic field-effect materials. ► Organic field-effect transistors were fabricated and a high mobility up to 0.54 cm2 V−1 s−1 was obtained. ► Single crystal micro/nano ribbons were prepared by a solution-phase self-assembly process. ► Single crystal field-effect transistors based on an individual microribbon were fabricated.
Co-reporter:LiPing Wang;ShiBo Jiao;WeiFeng Zhang;YunQi Liu;Gui Yu
Science Bulletin 2013 Volume 58( Issue 22) pp:2733-2740
Publication Date(Web):2013 August
DOI:10.1007/s11434-013-5786-2
Two novel zinc Schiff-base complexes, bis-(N-(2-hydroxybenzidene)-p-aminodimethylaniline)zinc(II) (2) and bis-(N-(2-hydroxy-1-naphthidene)-p-aminodimethylaniline)zinc(II) (4) were designed and synthesized. Both the complexes exhibit good solubility in organic solvents and excellent thermal stabilities. A single crystal of 2 was grown and its crystalline structure was determined from X-ray diffraction data. Analysis of the electronic structures of both the zinc complexes calculated by density functional theory reveals a localization of orbital. The UV-Vis absorption and photoluminescence profiles of 4 in thin film are similar to those of 2, but the emission for 4 is red-shifted compared to 2. Three-layered devices with a configuration of ITO/NPB/2/Alq3/LiF/Al and ITO/NPB/4/Alq3/LiF/Al show a yellow and red emission, respectively.
Co-reporter:Liping Wang, Xudong Xu, Xin Yuan
Journal of Luminescence 2010 Volume 130(Issue 1) pp:137-140
Publication Date(Web):January 2010
DOI:10.1016/j.jlumin.2009.07.036
Nanometer-sized Eu3+-doped ZnS and Mn2+-doped ZnS particles were prepared by solid-state method at low temperature. The structures and properties of those materials were characterized by X-ray diffraction (XRD) and photoluminescent spectroscopy techniques. The XRD patterns reveal that the doped ZnS nanoparticles belong to zinc-blende structure. The concentration of doping ions has little effect on the sizes of the doped ZnS nanoparticles, which mainly depends on the temperature of preparation. The emission peaks from the 5D0→7FJ (J=1, 2, and 4) electronic energy transitions of Eu3+ were observed in the emission spectra of the ZnS:Eu3+ nanoparticles. The intensity ratio of the two peaks from the 5D0→7F1 and 5D0→7F2 transitions indicates that more Eu3+ ions occupy the sites with no inversion symmetry. For the ZnS:Mn2+ nanoparticles, an orange emission from the 4T1→6A1 transition of Mn2+ is present, indicating that the doping ions occupy the positions of the ZnS lattices. Meanwhile, UV-induced luminescence enhancement was observed for the ZnS:Mn2+ nanoparticles, the possible reason of which is discussed primarily.
Co-reporter:Liping Wang, Chengming Zhao, Fanguo Meng, Shungang Huang, Xin Yuan, Xudong Xu, Zhou Yang, Huai Yang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2010 360(1–3) pp: 205-209
Publication Date(Web):
DOI:10.1016/j.colsurfa.2010.02.033
Co-reporter:Liping Wang, Baofang Li, Guangyan Hong
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2007 Volume 296(1–3) pp:57-61
Publication Date(Web):15 March 2007
DOI:10.1016/j.colsurfa.2006.09.023
The characteristics of intermediates of bacteriorhodopsin (bR) can be verified by chemical modification of its surroundings. CeO2 nanoparticles, which were obtained using water-in-oil (W/O) microemulsion and calcined at various temperatures, were used as chemical additive for the modification of bR. X-ray diffraction (XRD) shows that the mean particle sizes for the samples calcined at 500 and 800 °C are approximately 10 and 30 nm, respectively. We prepared CeO2 nanoparticle modified poly(vinyl alcohol) (bR-PVA) films with an optical density of about 1.5 at the ground state. It is observed that the lifetime of the M-intermediate for the modified films is prolonged compared with that of the unmodified ones, and the lifetime increases with decreasing particle size. A probable mechanism, which is likely to involve effective molecular interactions between the CeO2 nanoparticles and the bR molecules, is discussed. The hydroxyl groups, which might arise from the interaction between the nanoparticles and the surrounding water molecules, help to lower the ability of the Schiff base of uptaking protons in the M-intermediate. The results indicate that controlling the interactions between biomolecules and various nanomaterials would enlarge the functionality and the range of the application of nanoparticles.
Co-reporter:Liping Wang, Shungang Huang, Yujie Sun
Applied Surface Science (1 April 2013) Volume 270() pp:
Publication Date(Web):1 April 2013
DOI:10.1016/j.apsusc.2012.12.160
A general route to synthesize transition metal ions doped ZnS nanoparticles with hexagonal phase by means of a conventional reverse micelle at a low temperature is developed. The synthesis involves N,N-dimethylformamide, Zn(AC)2 solution, thiourea, ammonia, mercaptoacetic acid, as oil phase, water phase, sulfide source, pH regulator, and surfactant, respectively. Thiourea, ammonia and mercaptoacetic acid are demonstrated crucial factors, whose effects have been studied in detail. In addition, the FT-IR spectra suggest that mercaptoacetic acid may form complex chelates with Zn2+ in the preparation. In the case of Cu2+ as a doped ion, hexagonal ZnS:Cu2+ nanoparticles were synthesized at 95 °C for the first time. The X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements show that the ZnS:Cu2+ nanoparticles are polycrystalline and possess uniform particle size. The possible formation mechanism of the hexagonal doped ZnS is discussed.Highlights► Hexagonal ZnS synthesized for the first time at low temperature. ► The synthesis temperature can be as low as 95 °C. ► Sulfide source, surfactant, pH regulator, are crucial factors for the understanding of crystal structure. ► Possible reaction mechanism is discussed.
Co-reporter:Jianyao Huang ; Hao Luo ; Liping Wang ; Yunlong Guo ; Weifeng Zhang ; Huajie Chen ; Minliang Zhu ; Yunqi Liu ;Gui Yu
Organic Letters () pp:
Publication Date(Web):June 12, 2012
DOI:10.1021/ol3012748
Two structural isomers of six-fused-ring sulfur-containing molecules were synthesized as active materials for p-type organic field-effect transistors, and their optical and electrochemical properties were characterized. Field-effect transistors based on these compounds were fabricated to investigate the relationships between structures and semiconductor properties.
Co-reporter:Weifeng Zhang, Zupan Mao, Naihang Zheng, Jiabin Zou, Liping Wang, Congyuan Wei, Jianyao Huang, Dong Gao and Gui Yu
Journal of Materials Chemistry A 2016 - vol. 4(Issue 39) pp:NaN9275-9275
Publication Date(Web):2016/09/09
DOI:10.1039/C6TC02891H
It is meaningful to explore new design principles for organic semiconductors. Herein, we have developed two cross-conjugated alternating polymers based on 1,2-di(thiophen-2-yl)ethane-1,2-dione (DTO), namely PDTO-C1 and PDTO-C3, and investigated their charge transport properties by fabricating field-effect transistors devices. Single crystal X-ray crystallography shows that non-covalent S⋯O and C–H⋯O interactions exist inside the DTO units. These non-covalent interactions in combination with the C–H⋯O interactions of the thiophene-flanked dithienothiophene units, acting as conformational locks, are beneficial for acquiring the planar backbone conformation. PDTO-C1 and PDTO-C3 possess broad absorption spectra and HOMO and LUMO energy levels of ca. −5.50 and −3.6 eV, respectively. The highest mobility of 0.54 cm2 V−1 s−1 was achieved in the PDTO-C3-based transistor devices, whereas PDTO-C1 affords a mobility of 0.22 cm2 V−1 s−1. Further thin film microstructure investigations indicate that both polymers can form highly-ordered lamellar packing with small π–π stacking distances down to 3.50 Å. These results demonstrate that the incorporation of cross-conjugation may be used as an additional design tactic for organic semiconductors to alter their optoelectronic properties.
Co-reporter:Liping Wang, Xiaodong Xie, Weifeng Zhang, Ji Zhang, Mingshan Zhu, Yunlong Guo, Penglei Chen, Minghua Liu and Gui Yu
Journal of Materials Chemistry A 2014 - vol. 2(Issue 32) pp:NaN6490-6490
Publication Date(Web):2014/07/03
DOI:10.1039/C4TC00251B
High-performance organic phototransistors (OPTs) have been successfully constructed using bitriisopropylsilylethynyl tetraceno[2,3-b]thiophenes (TIPSEthiotet) or pentacene as a semiconductor layer. Fluorographene (FG) nanosheets were used to modify the interface between an organic semiconductor layer and gate dielectric. The effects of interface modification were investigated. It was found that enhanced photoresponsivity and a boosted photocurrent/dark-current ratio could be easily achieved after the implantation of modification layers. The constructed FG-modified devices based on TIPSEthiotet showed a maximum photoresponsivity of 21.83 A W−1 and a photocurrent/dark-current ratio of 1.85 × 106 under white light irradiation. Meanwhile, for the FG-modified OPT device based on pentacene, a high photoresponsivity of 144 A W−1 was obtained under white light irradiation with an optical power of as low as 25 μW cm−2. This photoresponsivity datum is higher than that of most OPTs based on pentacene reported under the same conditions. In addition, the mobilities of the devices could also be increased distinctly after the introduction of the FG-modified layer. The experimental facts indicate that the strong electron trapping ability of the fluorine atoms in the FG nanosheets and the well-known photovoltaic effect play an important role in these interesting results.
Co-reporter:Weifeng Zhang, Ji Zhang, Xiangyang Chen, Zupan Mao, Xiaodong Xie, Liping Wang, Yi Liao, Gui Yu, Yunqi Liu and Daoben Zhu
Journal of Materials Chemistry A 2013 - vol. 1(Issue 39) pp:NaN6410-6410
Publication Date(Web):2013/08/29
DOI:10.1039/C3TC31421A
In order to study the influence of molecular conformation on the packing mode of single crystals, four bitrialkylsilylethynyl thienoacenes, TIPS–ABT, TMS–ABT, TIPS–CABT and TMS–CABT, were synthesized and characterized. Since there are different conformations arising from the rotation of the isopropyl groups, two types of single crystals of the thienoacene TIPS–ABT were successfully grown, and the related quantum-chemical calculations predict that in theory they have significantly different hole mobilties (μh). For example, the μh of TIPS–ABT-1 is 1.74 cm2 V−1 s−1, a value nearly two hundred times larger than that of TIPS–ABT-2 (0.09 cm2 V−1 s−1), when the reorganization energy is obtained at the B3LYP/6-31+G(d) level. The results demonstrate the important influence of molecular conformation on the mode of crystal packing, and theoretically show the importance of organic semiconductor conformational control on the charge mobility. The thin film FET devices based on the four thienoacenes were prepared via the vacuum-deposit method. The TIPS–CABT-based devices afford hole mobilities of up to 0.012 cm2 V−1 s−1 with a current on–off ratio of 106.
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