XueQin Zhou

Effective charge separation is one of the key determinants for the photovoltaic performance of the dye-sensitized solar cells (DSSCs). Herein, two charge-separated (CS) sensitizers, MTPA-Pyc and YD-Pyc, have been synthesized and applied in DSSCs to investigate the effect of the CS states of the sensitizers on the device’s efficiency. The CS states with lifetimes of 64 and 177 ns for MTPA-Pyc and YD-Pyc, respectively, are formed via the photoinduced electron transfer (PET) from the 4-styryltriphenylamine (MTPA) or 4-styrylindoline (YD) donor to the pyrimidine cyanoacrylic acid (Pyc) acceptor. DSSCs based on MTPA-Pyc and YD-Pyc exhibit high internal quantum efficiency (IQE) values of over 80% from 400 to 600 nm. In comparison, the IQEs of the charge transfer (CT) sensitizer cells are 10–30% lower in the same wavelength range. The enhanced IQE values in the devices based on the CS sensitizers are ascribed to the higher electron injection efficiencies and slower charge recombination. The results demonstrate that taking advantage of the CS states in the sensitizers can be a promising strategy to improve the IQEs and further enhance the overall efficiencies of the DSSCs.Keywords: charge recombination; charge-separated (CS) sensitizers; electron injection; internal quantum efficiency (IQE); photoinduced electron transfer (PET);

Synthesis and characterization of triphenylamine modified azobenzene dyes

Co-reporter:Chuanwu Zhao, Tianyang Wang, Dongmei Li, Ting Lu, Dongzhi Liu, Qingbo Meng, Qianqian Zhang, Fengqing Li, Wei Li, Wenping Hu, Lichang Wang, Xueqin Zhou

Dyes and Pigments 2017 Volume 137() pp:256-264

Publication Date(Web):February 2017

DOI:10.1016/j.dyepig.2016.10.018

•Four new triphenylamine modified azobenzene dyes were synthesized.•Donor-acceptor-donor structure was characterized for these dyes.•HOMO, light absorption ability and hole mobility can be improved by varying the substitutions.•The dyes display applications in pervoskite solar cells as hole transport materials.A series of triphenylamine modified azobenzenes were synthesized and studied theoretically and experimentally. D-A-D structures of these dyes were revealed with an intramolecular charge transfer (ICT) from both triphenylamine or indoline units (donor) to the central azobenzene unit (acceptor). Both computational and experimental results indicate that a stronger electron donating ability of the donor enhances the degree of ICT and improve their HOMO energies. The absorption spectra indicate an increased light absorption by enhanced ICT effect. The intermolecular interaction also affects their absorption ability. The strongest intermolecular interaction results in the best light absorption ability in films. An obviously increased hole mobility was also found as the ICT was enhanced. These dyes were used as hole transport materials (HTM) of perovskite solar cells to investigate their feasibility. It is revealed that the solubility and filming ability are significant for the photovoltaic performance of devices.

Solid-state nanocrystalline solar cells with an antimony sulfide absorber deposited by an in situ solid–gas reaction

Co-reporter:Li Zheng;Kejian Jiang;Jinhua Huang;Yu Zhang;Bin Bao;Huijia Wang;Bo Guan;Lian Min Yang;Yanlin Song

Journal of Materials Chemistry A 2017 vol. 5(Issue 10) pp:4791-4796

Publication Date(Web):2017/03/07

DOI:10.1039/C7TA00291B

An Sb2S3 absorber layer is coated on mesoporous TiO2 films through a sequential deposition method: SbCl3 aqueous solution is first deposited, followed by reaction with H2S gas and further thermal annealing. Under our conditions, the Sb2S3-based solid-state heterojunction solar cells yield efficiencies of up to 6.27% at 100 mW cm−2 AM 1.5 G.

Characterization of photo-induced electron and hole transfer in a porphyrin based ambipolar organic molecule with cascade energy levels

Co-reporter:Tianyang Wang, Krishanthi C. Weerasinghe, Haiya Sun, Ping'an Li, Dongzhi Liu, Wei Li, Wenping Hu, Xueqin Zhou, Lichang Wang

Journal of Molecular Structure 2017 Volume 1142(Volume 1142) pp:

Publication Date(Web):15 August 2017

DOI:10.1016/j.molstruc.2017.04.079

•D-A1-A2 architectural ambipolar organic semiconductor was synthesized.•Characterization of photoinduced electron and hole transfer was achieved.•Both transfers were more effective in dichloromethane than those in toluene.A porphyrin based ambipolar organic molecule consisting of styrene based triphenylamine derivative (MTPA) as electron donor, s-triazine group (TRC) as electron acceptor 1 and metal-free tetraphenyl porphyrin (HTPP) as electron acceptor 2 was synthesized and characterized using computational methods and electrochemical and spectroscopic measurements. The kinetics analysis indicates that the photo-induced charge-separated states, MTPA.+-TRC-HTPP.-, were generated by sequential electron transfers from MTPA to TRC then to HTPP and/or a direct hole transfer from HTPP to MTPA. In toluene, the charge-separated states were formed with 54% through electron transfer and 46% through hole transfer once MTPA moiety was excited. However, in dichloromethane, they were formed with 75% through electron transfer and 25% through hole transfer. Furthermore, more charge-separated species were generated in dichloromethane than in toluene.

Using glycine-induced nanoparticle to enhance photo-induced electron transfer efficiency in donor-acceptor system

Co-reporter:Fengqing Li, Tianyang Wang, Li Wang, Chuanwu Zhao, Fan Yang, Haiya Sun, Dongzhi Liu, Wenping Hu, Wei Li, Xueqin Zhou

Dyes and Pigments 2017 Volume 140(Volume 140) pp:

Publication Date(Web):1 May 2017

DOI:10.1016/j.dyepig.2017.01.040

•Designed and synthesized a new glycine based porphyrin-oxadiazole dyad.•The glycine moiety enhanced the photo-induced electron transfer efficiency of the dyad, and led to regular aggregates.•The glycine moiety enhanced the photo-induced electron transfer efficiency in nanoparticles.The glycine moiety was introduced to the porphyrin-oxadiazole compound through the s-triazine group. Regular nanoparticles were assembled by the newly synthesized compound using surfactant-assistant self-assembly method. The morphology of nanoparticles was characterized by scanning electron microscopy and X-ray diffraction analysis. The photo-physical properties of both the monomer and nanostructure in solvent were characterized by UV–visible, steady-state and transient fluorescence spectra, indicating that the glycine moiety enhanced the efficiency of photo-induced electron transfer from excited porphyrin to oxadiazole module in the monomer and nanoparticle of the new dyad.

Dissociation exists in s-triazine based donor-accepter organic systems by photo-induced electron transfer

Co-reporter:Tianyang Wang, Haiya Sun, Ting Lu, Chelsea N. Bridgmohan, Fengqing Li, Dongzhi Liu, Wenping Hu, Wei Li, Xueqin Zhou, Lichang Wang

Dyes and Pigments 2017 Volume 139(Volume 139) pp:

Publication Date(Web):1 April 2017

DOI:10.1016/j.dyepig.2016.12.030

•Introducing the electron-deficient chromophore as acceptor 2 to donor-acceptor module increases its light-stability.•Transferring the photo-induced electron to acceptor 2.•Therefore by preventing the dissociation of chloride anion in the donor-acceptor systems.In the organic donor-acceptor system, the dissociation of the chloride anion in the s-triazine group as the acceptor was first investigated under irradiation. Introducing the electron-deficient chromophore as acceptor 2 to the donor-acceptor module allows the photo-induced electron transfer from the s-triazine module, making the dissociation less in the donor-acceptor1-acceptor2 architecture, which has been proven to be a good strategy to increase light-stability.Download high-res image (170KB)Download full-size image

Effect of photo-induced charge separated state lifetimes in donor-acceptor1-acceptor2 organic ambipolar semiconductors on their photovoltaic performances

Co-reporter:Tianyang Wang, Haiya Sun, Linli Zhang, Nathan D. Colley, Chelsea N. Bridgmohan, Dongzhi Liu, Wenping Hu, Wei Li, Xueqin Zhou, Lichang Wang

Dyes and Pigments 2017 Volume 139(Volume 139) pp:

Publication Date(Web):1 April 2017

DOI:10.1016/j.dyepig.2016.12.066

•A newly fullerene based donor-acceptor1-acceptor2 system was synthesized and characterized.•The lifetime of charge-separated state of the new system was up to 7.9 μs.•Long-lived CS states were playing an important role in promoting photoelectric conversion.A newly ambipolar organic semiconductor with styrene based indoline derivative (YD) as the electron donor (D), s-triazine group (TRC) as the electron acceptor (A1), and fullerene derivative (NMF) as the second electron acceptor (A2) has been synthesized and characterized, which had a charge-separated state of 7.9 μs, corresponding to a 37 fold increase in comparison with the 215 ns lifetime of the D-A1 precursor. Here we compared photovoltaic properties of YD-TRC-NMF with those of other four D-TRC-A2 systems, which replaced indoline with triphenylamine (MTPA) and fullerene with perylene bisimide or anthraquinone (AEAQ), indicating that long-lived CS states are playing an important role in promoting photoelectric conversion in YD-TRC-AEAQ (or NMF) and MTPA-TRC-AEAQ, in which the short-circuit current and photoelectric conversion efficiency were significantly improved in comparison with YD-TRC and MTPA-TRC, respectively, due to triplet states of A2 being higher than charge-separated states. This proves that a general D-A1-A2 architecture can become a reasonable materials design strategy for photovoltaics.Download high-res image (249KB)Download full-size image

Enhancing Photoinduced Charge Separation through Donor Moiety in Donor–Acceptor Organic Semiconductors

Co-reporter:Tianyang Wang, Chuanwu Zhao, Linli Zhang, Ting Lu, Haiya Sun, Chelsea N. Bridgmohan, Krishanthi C. Weerasinghe, Dongzhi Liu, Wenping Hu, Wei Li, Xueqin Zhou, and Lichang Wang

The Journal of Physical Chemistry C 2016 Volume 120(Issue 44) pp:25263-25275

Publication Date(Web):October 19, 2016

DOI:10.1021/acs.jpcc.6b09352

Three systems were designed, synthesized, and characterized to understand decay processes of photoinduced charge separation in organic semiconductors that are imperative for efficient solar energy conversion. A styrene-based indoline derivative (YD) was used as donor moiety (D), a triazine derivative (TRC) as the first acceptor (A1), and 9,10-anthraquinone (AEAQ) as a second acceptor (A2) in constructing two systems, YD-TRC and YD-TRC-AEAQ. The lifetime of the photoinduced charge-separated states in YD-TRC, a D–A1 system, was found to be 215 ns and that in YD-TRC-AEAQ, a D–A1–A2 system, to be 1.14 μs, a 5-fold increase with respect to that of the YD-TRC. These results show that YD is a more effective donor in YD-TRC and YD-TRC-AEAQ systems at forming long-lived charge-separated states compared to a previously reported atriphenylamine derivative (MTPA) that generated charge-separated states with a lifetime of 80 ns in MTPA-TRC and 650 ns in MTPA-TRC-AEAQ. The third system was constructed using a metal-free porphyrin derivative (MHTPP) to form a MHTPP-TRC-AEAQ structure, a D–L (linker)–A system with a charge separation lifetime less than 10 ns. Therefore, the D–A1–A2 architecture is the best at generating long-lived charge-separated states and thus is a promising design strategy for organic photovoltaics materials.

Construction of Ag/AgCl nanostructures from Ag nanoparticles as high-performance visible-light photocatalysts

Co-reporter:Fan Yang;Dongzhi Liu;Tianyang Wang;Wei Li

Journal of Nanoparticle Research 2016 Volume 18( Issue 11) pp:

Publication Date(Web):2016 November

DOI:10.1007/s11051-016-3658-9

A combined strategy of in situ oxidation and assembly is developed to prepare Ag/AgCl nanospheres and nanocubes from Ag nanoparticles under room temperature. It is a new facile way to fabricate Ag/AgCl with small sizes and defined morphologies. Ag/AgCl nanospheres with an average size of 80 nm were achieved without any surfactants, while Ag/AgCl nanocubes with a mean edge length of 150 nm were obtained by introduction of N-dodecyl-N,N-dimethyl-2-ammonio-acetate. The possible formation mechanism involves the self-assembly of AgCl nanoparticles, Ostwald ripening and photoreduction of Ag+ into Ag0 by the room light. The as-prepared Ag/AgCl nanospheres and nanocubes exhibit excellent photocatalytic activity and stability toward degradation of organic pollutants under visible-light irradiation. It is demonstrated that Ag/AgCl nanocubes display enhanced photocatalytic activity in comparison with Ag/AgCl nanospheres due to the more efficient charge transfer. This work may pave an avenue to construct various functional materials via the assembly strategy using nanoparticles as versatile building blocks.

Effect of Triplet State on the Lifetime of Charge Separation in Ambipolar D-A1-A2 Organic Semiconductors

Co-reporter:Tianyang Wang

The Journal of Physical Chemistry C 2016 Volume 120(Issue 21) pp:11338-11349

Publication Date(Web):April 28, 2016

DOI:10.1021/acs.jpcc.6b01321

An ambipolar organic semiconductor with styrene based triphenylamine derivative (MTPA) as an electron donor (D), triazine group (TRC) as an electron acceptor (A1), and 9,10-anthraquinone (AEAQ) as a second electron acceptor (A2) has shown an 8-fold increase in the lifetime of charge separation with a high performance as solar cell materials with respect to the D-A1 architecture and demonstrated a general D-A1-A2 architecture as a promising materials design strategy for photovoltaics. Here we synthesized and characterized two new D-A1-A2 compounds with perylene bisimide derivatives (PDI and PBI) as A2 using an integrated experimental and computational method to study and compare the kinetics of three MTPA-TRC-A2 systems. A two-step sequential decay pathway was observed in both MTPA-TRC-PDI and MTPA-TRC-PBI but a direct decay pathway in MTPA-TRC-AEAQ. The charge separated state with a lifetime of 22 ns in the PDI system and 75 ns in the PBI system relaxes to the corresponding triplet state followed by the decay to ground state in 827 ns and 29.2 μs, respectively. Thus, a triplet state with a lower energy than the charge separated state shortens the lifetime of the charge separated state but increases the overall lifetime of excited states.

A push–pull thienoquinoidal chromophore for highly efficient p-type dye-sensitized solar cells

Co-reporter:Qian-Qian Zhang, Ke-Jian Jiang, Jin-Hua Huang, Chuan-Wu Zhao, Li-Peng Zhang, Xue-Ping Cui, Mei-Ju Su, Lian-Ming Yang, Yan-Lin Song and Xue-Qin Zhou

Journal of Materials Chemistry A 2015 vol. 3(Issue 15) pp:7695-7698

Publication Date(Web):10 Mar 2015

DOI:10.1039/C5TA01348H

A push–pull thienoquinoidal chromophore, 4,4′-((4-((5-(dicyanomethylene)thiophen-2(5H)-ylidene) methyl)phenyl) azanediyl) dibenzoic acid (QT-1), was synthesized and used as a sensitizer in a p-DSC, giving a short-circuit photocurrent density of 8.2 mA cm−2 under standard AM 1.5 conditions.

Inkjet printing of CH3NH3PbI3 on a mesoscopic TiO2 film for highly efficient perovskite solar cells

Co-reporter:Shao-Gang Li, Ke-Jian Jiang, Mei-Ju Su, Xue-Ping Cui, Jin-Hua Huang, Qian-Qian Zhang, Xue-Qin Zhou, Lian-Min Yang and Yan-Lin Song

Journal of Materials Chemistry A 2015 vol. 3(Issue 17) pp:9092-9097

Publication Date(Web):03 Dec 2014

DOI:10.1039/C4TA05675B

An inkjet printing technique is successfully used to deposit a perovskite CH3NH3PbI3 layer on a mesoscopic TiO2 film. With combined optimization of the table temperature and the ink composition, a flat and uniform perovskite layer is realized on the TiO2 film, and the corresponding photovoltaic device exhibits a high efficiency of 12.3% with an average value of 11.2% under AM 1.5G conditions. The current work demonstrates that the inkjet printing method is environmentally benign and cost-effective with reduced waste of the toxic Pb-containing materials encountered inevitably in the existing techniques during the device preparation.

Electrodeposition of PbO and its in situ conversion to CH3NH3PbI3 for mesoscopic perovskite solar cells

Co-reporter:Xue-Ping Cui, Ke-Jian Jiang, Jin-Hua Huang, Xue-Qin Zhou, Mei-Ju Su, Shao-Gang Li, Qian-Qian Zhang, Lian-Min Yang and Yan-Lin Song

Chemical Communications 2015 vol. 51(Issue 8) pp:1457-1460

Publication Date(Web):28 Nov 2014

DOI:10.1039/C4CC08269A

The perovskite CH3NH3PbI3 was prepared on a mesoscopic TiO2 film, starting from electrodepositing PbO, to iodination to PbI2, and then interdiffusion reaction with CH3NH3I. The as-prepared film was used as a light absorber for the perovskite solar cells, exhibiting a high PCE of 12.5% under standard AM 1.5 conditions.

Small molecular thienoquinoidal dyes as electron donors for solution processable organic photovoltaic cells

Co-reporter:Mei-Ju Su, Jin-Hua Huang, Li-Peng Zhang, Qian-Qian Zhang, Chuan-Lang Zhan, Xue-Qin Zhou, Lian-Ming Yang, Yanlin Song and Ke-Jian Jiang

RSC Advances 2015 vol. 5(Issue 94) pp:76666-76669

Publication Date(Web):04 Sep 2015

DOI:10.1039/C5RA15956C

Two small molecular quinoidal thiophene dyes, featuring quinoidal thiophene as a spacer, N,N-diethylaniline or N,N-bis(p-methylphenyl)aniline as an electron donor moiety, and dicyanomethylene as an electron acceptor moiety, have been synthesized as donors for organic photovoltaic cells, and a best power conversion efficiency of 5.12% has been achieved.

Tuning electron–hole distance of the excitons in organic molecules using functional groups

Co-reporter:Tianyang Wang, Krishanthi C. Weerasinghe, Pamela C. Ubaldo, Dongzhi Liu, Wei Li, Xueqin Zhou, Lichang Wang

Chemical Physics Letters 2015 Volume 618() pp:142-146

Publication Date(Web):2 January 2015

DOI:10.1016/j.cplett.2014.10.072

•Exciton size increases with the electron withdrawing ability of a functional group.•Exciton size correlates the absorption and fluorescence wavelength quadratically.•Exciton size correlates the Stokes shift quadratically.•Emission lifetime shows a volcano-type dependence on the size of excitons.•Charge separated excitons have a decay lifetime of about 200 ps.Understanding and tuning photogenerated excitons in organic materials are crucial for high performance organic photovoltaics. Using a combined experimental and computational approach, we designed seven triphenylamine-based molecules to generate excitons with a size range of 2.0–8.6 Å. The absorption and fluorescence wavelengths of the molecules increase quadratically with the size of excitons generated while the fluorescence emission lifetime shows a volcano plot. The charge separated excitons were identified with a decay lifetime of about 200 ps. This work opens up a new way of studying organic supramolecules, polymers, and bulk materials for efficient organic photovoltaics and photocatalysis.

Cupric bromide hybrid perovskite heterojunction solar cells

Co-reporter:Xue-Ping Cui, Ke-Jian Jiang, Jin-Hua Huang, Qian-Qian Zhang, Mei-Ju Su, Lian-Ming Yang, Yan-Lin Song, Xue-Qin Zhou

Synthetic Metals 2015 Volume 209() pp:247-250

Publication Date(Web):November 2015

DOI:10.1016/j.synthmet.2015.07.013

•Two layered cupric bromide hybrid perovskites are prepared.•The perovskites were employed as light absorbers for heterojunction solar cells.•The perovskite-based device exhibited a best power conversion efficiency of 0.63%.Currently, the hybrid perovskite solar cells were exclusively dominated by the Pb or Sn-based perovskite materials, and these materials, however, exhibit long term instabilities associated with ambient hydrolysis and oxidation, limiting their widespread applications. In this work, two layered cupric bromide hybrid perovskite compounds are prepared as light absorbers for application in heterojunction solar cells. The perovskite layers can be deposited from the solutions of the as-prepared perovskites or directly from their precursor solutions at ambient condition. Their preliminary phoyovoltaic performance was carried out in mesoporous TiO2 heterojunction solar cells.Two layered cupric bromide hybrid perovskite compounds are prepared as light absorbers for application in heterojunction solar cells. The perovskite layers can be deposited from the solutions of the as-prepared perovskites or directly from their precursor solutions. Their preliminary phoyovoltaic performance was carried out in mesoporous TiO2 heterojunction solar cells.

Ambipolar organic semiconductors with cascades of energy levels for generating long-lived charge separated states: a donor–acceptor1–acceptor2 architectural triarylamine dye

Co-reporter:Tianyang Wang, Krishanthi C. Weerasinghe, Dongzhi Liu, Wei Li, Xilong Yan, Xueqin Zhou and Lichang Wang

Journal of Materials Chemistry A 2014 vol. 2(Issue 28) pp:5466-5470

Publication Date(Web):20 May 2014

DOI:10.1039/C4TC00860J

A donor–acceptor1–acceptor2 architectural 4-styryltriphenyl amine-based organic semiconductor was synthesized for solar cell applications. Sequential electron transfers together with effective hole transfer lead to a charge separated state lifetime of 650 ns, therefore boosting the short circuit current and efficiency of single layer organic photovoltaic cells.

Tuning the photophysical, thermal properties and electronic energy levels in the triphenylamine derivatives by benzoylhydrazone architecture

Co-reporter:Lizeng Liu, Xianfang Meng, Wei Li, Xueqin Zhou, Zhengchen Bai, Dongzhi Liu, Yunrong Lv, Rui-hong Li

Dyes and Pigments 2014 Volume 108() pp:32-40

Publication Date(Web):September 2014

DOI:10.1016/j.dyepig.2014.04.021

•The five triphenylamine derivatives modified by benzoylhydrazone structure were synthesized.•The effects of the electron-withdrawing/donating group were confirmed by density functional study and photophysical properties.•The thermostability and electrochemistry properties of the five compounds were found to be distinctively promoted.A novel of triphenylamine derivatives with more extended π-conjugated systems achieved by benzoylhydrazone architecture were synthesized under mild condition with high yields. The dependence of their photophysical, electrochemistry and thermal properties on their chemical structure is discussed. Compared with the N,N-di(4-methylphenyl)aniline, the thermostability of the five triphenylamine-based hydrozones is dramatically promoted. These compounds are stable up to 345 °C according to thermogravimetric analysis. The energy levels of the four compounds were finely tuned by introducing the electron-donating and -withdrawing groups to the triphenylamine core which are supported by the fluorescence spectra and transit fluorescence spectra of the compounds (–H > –CH3 > –Cl > Pyridine > –NO2). Their multiple cyclic voltammetry study and density functional study suggest these materials to be promising hole-transport properties.

Enhanced dispersibility and dispersion stability of dodecylamine-protected silver nanoparticles by dodecanethiol for ink-jet conductive inks

Co-reporter:Xueqin Zhou, Wei Li, Meilan Wu, Shen Tang, Dongzhi Liu

Applied Surface Science 2014 Volume 292() pp:537-543

Publication Date(Web):15 February 2014

DOI:10.1016/j.apsusc.2013.12.006

Highlights

•: Silver nanoparticles with excellent dispersibility and dispersion stability were synthesized by mixed protective agents.
•: Slow sintering of silver nanoparticles occurs spontaneously at room temperature.
•: The resistivity of ink-jet printing patterns on PI substrate is 7.2 μΩ cm after 10 min heat-treatment at 130 °C.

The negative temperature coefficient resistivities of Ag2SAg core–shell structures

Co-reporter:Mingming Yu, Dongzhi Liu, Wei Li, Xueqin Zhou

Applied Surface Science 2014 Volume 288() pp:158-165

Publication Date(Web):1 January 2014

DOI:10.1016/j.apsusc.2013.09.172

•Excellent negative temperature coefficient resistivities were found with annealed films of silver nanoparticles protected with 3-mercaptopropionic acid (Ag/MPA).•Ag/MPA nanoparticles were found to convert into stable Ag2SAg core–shell structures when annealed in air at 200 °C.•A possible mechanism for the formation of Ag2SAg core–shell structures was proposed.In this paper, the conductivity of silver nanoparticle films protected by 3-mercaptopropionic acid (Ag/MPA) has been investigated. When the nanoparticles were annealed in air at 200 °C, they converted to stable Ag2SAg core–shell structures. The mechanism for the formation of the Ag2SAg core–shell structures along with the compositional changes and the microstructural evolution of the Ag/MPA nanoparticles during the annealing process are discussed. It is proposed that the Ag2SAg core–shell structure was formed through a solid-state reduction reaction, in which the Ag+ ions coming from Ag2S were reduced by sulfonate species and sulfur ions. The final Ag2SAg films display an exponentially decreased resistivity with increasing temperature from 25 to 170 °C. The negative temperature coefficient resistivity of Ag2SAg films can be adjusted by changing the S/Ag molar ratio used for the synthesis of the Ag/MPA nanoparticles, paving the way for the preparation of negative temperature-coefficient thermistors via printing technology for use in the electronics.

Effects of dodecylamine and dodecanethiol on the conductive properties of nano-Ag films

Co-reporter:Lixin Mo, Dongzhi Liu, Wei Li, Luhai Li, Lichang Wang, Xueqin Zhou

Applied Surface Science 2011 Volume 257(Issue 13) pp:5746-5753

Publication Date(Web):15 April 2011

DOI:10.1016/j.apsusc.2011.01.090

Abstract

Nano-Ag particles, with dodecylamine (DDA) and dodecanethiol (DDT) as the protective agent, were prepared and studied in order to investigate the effect of protective agent in the post heat-treatment of nano-Ag films. Results of electrical resistivity, micro-structural evolution and thermal analysis showed that the Ag–DDA films require a lower treatment temperature to convert into conductive materials compared to that of the Ag–DDT films. And the Ag–DDA films also have lower final electrical resistivity as well as more uniform and dense microstructure in comparison with the Ag–DDT films. Further study indicated that Ag–DDA films are thermodynamically unstable and the sinter of Ag–DDA particles could occur spontaneously even at room temperature. FT-IR, ¹H NMR and X-ray diffraction determinations revealed that both DDA and DDT molecules coordinate to the surface of nano-Ag particles through their head-groups. The bonding energy of Ag–S is higher than that of Ag–N and the alkyl chains ordering of chemisorbed DDT is also higher than that of chemisorbed DDA. It is implied that the post heat-treatment temperature and final resistivity of nano-Ag films are associated with the bonding energy and configuration of different capping molecules. Finally the conductive ink was prepared with well dispersed Ag–DDA nanoparticles and the ink-jet printed patterns on PI films show a sheet resistance of 166 mΩ/□ after heat-treating at 140 °C for 60 min.

Photoinduced energy and electron transfer in porphyrin-anthraquinone dyads bridged with a triazine group

Co-reporter:Minli Tao, Lizeng Liu, Dongzhi Liu, Xueqin Zhou

Dyes and Pigments 2010 Volume 85(1–2) pp:21-26

Publication Date(Web):April 2010

DOI:10.1016/j.dyepig.2009.09.012

Porphyrin-anthraquinone dyads containing a triazine group as linker were synthesized and characterized by 1H NMR, UV–visible, fluorescence and transient spectra and ESI-MS. Absorption spectra revealed that there was no appreciable interaction between the ground-state porphyrin moiety and the ground-state anthraquinone moiety. Fluorescence spectra illustrated that energy transfer takes place from the excited anthraquinone moiety to the porphyrin moiety when excited at 250 nm, whilst efficient electron transfer occurs from the singlet excited porphyrin moiety to the anthraquinone moiety in the case of excitation at 420 nm. A long-lived, charge-separated state H2P+–EQ− was observed by transient absorption spectra with a lifetime of 1.42 μs and 1.33 μs. These photochemical events were explained from electrochemical studies and suggest that the compounds have the ability to simulate electron transfer from chlorophylls to electron acceptors.

Effect of low molecular weight chitosans on drug permeation through mouse skin: 1. Transdermal delivery of baicalin

Co-reporter:Xueqin Zhou;Dongzhi Liu;Haiyan Liu;Qiaoli Yang;Kangde Yao;Xueyan Wang;Lei Wang;Xinjian Yang

Journal of Pharmaceutical Sciences 2010 Volume 99( Issue 7) pp:2991-2998

Publication Date(Web):

DOI:10.1002/jps.22063

Abstract

The aim of this work was to evaluate the low molecular weight chitosans (LMWCs) as enhancers of transdermal administration of baicalin, an useful drug for the treatment of atopic dermatitis, viral hepatitis, and HIV infection. Permeation experiments were performed in vitro through mouse skin by using Franz cells. Improved baicalin skin penetration was obtained with the addition of LMWCs or D-glucosamine (β-D-GlcNH₂) to the donor solutions. Chitosan molecular weight, degree of deacetylation, pH of donor baicalin solutions, and enhancer concentration all affected LMWC enhancement effects. Significant enhancement was observed at pH 7.0 or 7.5 for CS80-1000, and the enhancement factor (EF) in the co-delivery method was calculated as 11.7 or 15.9, respectively. Simultaneously, β-D-GlcNH₂ showed greatest enhancement at pH 7.0 with an EF of 11. Moreover, there was an optimal concentration range (0.5–1% by weight for CS80-1000 and 1.0–1.5% for β-D-GlcNH₂) to enhance baicalin transdermal delivery. It was concluded that the effective fractions for the enhancement of LMWCs were β-D-GlcNH₂ oligomers, and the repeated number of β-D-GlcNH₂ was suggested to be in the range 2–6. Enhancement mechanism of LMWCs was also discussed and suggested to be relative to the interactions of LMWC with both baicalin and the lipid of stratum corneum. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:2991–2998, 2010

A novel cataplasma matrix of traditional Chinese medicine

Co-reporter:Jing Tian;Xiaolei Zhang

Frontiers of Chemical Science and Engineering 2010 Volume 4( Issue 1) pp:91-95

Publication Date(Web):2010 March

DOI:10.1007/s11705-009-0304-4

The aim of this paper was to develop a cataplasma matrix that can be applicable to both water-soluble and liposoluble drugs. The gellan gum and konjaku were employed as the scaffold materials of the matrix. With polyacrylic acid sodium and oligosaccharides as tacktifier, the formula of the cataplasma matrix was optimized in the orthogonal method as: gellan gum 0.4 g, xanthan gum 0.03 g, konjac glue 0.1 g, glycerin 4 g, Gluco-Adhesive T (GAT) 6 g, Gluco-Adhesive E (GAE) 6 g, polyacrylic acid sodium 0.22 g, and sorbitol 3 g. The 180° peel strength, the tensile strength and the elongation at break was 3.043 N, 0.275 MPa and 91.05%, respectively. Furthermore, the drug-compatibilities of the matrix were investigated with baicalin, berberine and curcumin, which were used as the models of hydrophilic, poor-water-soluble and hydrophobic ingredients. The drug contents could reach 4.12%, 2.42% and 3.75%, while the in vitro release rate were measured as, 361.79, 55.85 and 104.41 μg·cm−2·h−1 for baicalin, berberine and curcumin, respectively. These results indicated that the obtained matrix had good drug-compatibility and drug-release properties for different ingredients.

Solid-state nanocrystalline solar cells with an antimony sulfide absorber deposited by an in situ solid–gas reaction

Co-reporter:Li Zheng, Kejian Jiang, Jinhua Huang, Yu Zhang, Bin Bao, Xueqin Zhou, Huijia Wang, Bo Guan, Lian Min Yang and Yanlin Song

Journal of Materials Chemistry A 2017 - vol. 5(Issue 10) pp:NaN4796-4796

Publication Date(Web):2017/02/09

DOI:10.1039/C7TA00291B

A push–pull thienoquinoidal chromophore for highly efficient p-type dye-sensitized solar cells

Co-reporter:Qian-Qian Zhang, Ke-Jian Jiang, Jin-Hua Huang, Chuan-Wu Zhao, Li-Peng Zhang, Xue-Ping Cui, Mei-Ju Su, Lian-Ming Yang, Yan-Lin Song and Xue-Qin Zhou

Journal of Materials Chemistry A 2015 - vol. 3(Issue 15) pp:NaN7698-7698

Publication Date(Web):2015/03/10

DOI:10.1039/C5TA01348H

Ambipolar organic semiconductors with cascades of energy levels for generating long-lived charge separated states: a donor–acceptor1–acceptor2 architectural triarylamine dye

Co-reporter:Tianyang Wang, Krishanthi C. Weerasinghe, Dongzhi Liu, Wei Li, Xilong Yan, Xueqin Zhou and Lichang Wang

Journal of Materials Chemistry A 2014 - vol. 2(Issue 28) pp:NaN5470-5470

Publication Date(Web):2014/05/20

DOI:10.1039/C4TC00860J

Inkjet printing of CH3NH3PbI3 on a mesoscopic TiO2 film for highly efficient perovskite solar cells

Co-reporter:Shao-Gang Li, Ke-Jian Jiang, Mei-Ju Su, Xue-Ping Cui, Jin-Hua Huang, Qian-Qian Zhang, Xue-Qin Zhou, Lian-Min Yang and Yan-Lin Song

Journal of Materials Chemistry A 2015 - vol. 3(Issue 17) pp:NaN9097-9097

Publication Date(Web):2014/12/03