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oe1(光电查) - 科学论文

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出版时间
  • 2019
研究主题
  • Dye-sensitized solar cell
  • Photoelectrode
  • Light scattering layer
  • Transmittance
  • White pigment (R902+)
  • Rutile titanium dioxide
应用领域
  • Optoelectronic Information Materials and Devices
机构单位
  • Tribhuvan University
352 条数据
?? 中文（中国） ▾

  • Effect of Electron Withdrawing/Donating Groups on the Sensitizing Action of the Novel Organic Dye a??3-(5-(4-(diphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acida?? for N-type Dye Sensitized Solar Cells: A Theoretical Study

    摘要： Computational studies using DFT and TDDFT approaches have been performed to study a series of metal free donor-π-acceptor (D-π-A) dyes. Taking the novel organic D5 dye (3-(5-(4-(diphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acid) as the primary structure, with triphenylamine as the donor, cyanoacrylic acid as the acceptor and a thiophene group as the π-linker, we have studied the effect of the substitution of different electron withdrawing and electron donating groups at different positions on the dye efficiency, by analyzing the geometry, charge distribution, electron injection and absorbance spectra. Electron injection has also been addressed for the substituted dyes immobilized on TiO2. Our calculations show that adding electron withdrawing groups at specific positions will lead to a higher efficiency of the dye.

    关键词： TDDFT,electron withdrawing groups,DFT,electron donating groups,dye sensitized solar cells,D5 dye

    更新于2025-09-23 15:19:57

  • Direct dynamic evidence of charge separation in a dyea??sensitized solar cell under operando conditions by Raman spectroscopy

    摘要： Interfaces play an important role in enhancing the energy conversion performance of dye-sensitized solar cells (DSCs). The interface effects have been studied by many techniques, but almost all studies only performed on a portion of DSC, rather than on a complete solar cell. Hence, monitoring the interface evolution of a DSC is still very challenging. Here, in situ/operando resonance Raman (RR) spectroscopic analyses were carried out to monitor the dynamic observations of the photovoltaic conversion process from a DSC. We observed the creation of new species (i.e., polyiodide and iodine aggregates) in the photosensitization process. We also successfully identified molecular-scale dynamic evidence that the bands from the C═C of 2,2’-bipyridyl (bpy), the S═C═N of NCS ligand and photochemical products show reasonably strong intensity and frequency changes, which clearly demonstrates that they are important pathways of charge separation. Furthermore, RR spectroscopy also be applicable to quickly evaluate the performance of DSCs.

    关键词： dye-sensitized solar cell,semiconductor,TiO2 nanotube array,Raman spectroscopy,charge transfer

    更新于2025-09-23 15:19:57

  • Application of Co-Mo bimetal/carbon composite in dye-sensitized solar cells and its research on synergy mechanism

    摘要： Bimetal/carbon aerogels have many advantages, such as nano-scale properties, low density, large specific surface area, and high porosity, but their application in dye-sensitized solar cells (DSSCs) as a counter electrode (CE) instead of noble metal Pt is relatively rare. In this paper, a low-cost sodium alginate was used to obtain a Co-Mo bimetal/carbon composite through a simple and controlled carbonization process. Using them as CEs of ZnO-based DSSCs, the filling characteristics of dye can be effectively improved. When the Co2+/Mo2+ molar ratio is 1:3, the photoelectric conversion efficiency of Co-Mo bimetal/ carbon composite–based DSSCs is close to the photoelectric conversion efficiency of Pt based, which is considered to be the result of the synergy of the carbon and two metal ions.

    关键词： Counter electrode,Bimetal/carbon composite,Synergy,Dye-sensitized solar cells,Aerogel

    更新于2025-09-23 15:19:57

  • Nickel sulphide-reduced graphene oxide composites as counter electrode for dye-sensitized solar cells: Influence of nickel chloride concentration

    摘要： Nickel sulphide-reduced graphene oxide (NiS-rGO) composite ?lms have been prepared via modi?ed Hummers’s method assisted with spin coating technique. The NiS-rGO samples were then employed as counter electrode in a dye-sensitized solar cell (DSSC). The main aim of this work is to investigate the relationship between the concentrations of NiCl2 with the properties of NiS-rGO and performance parameters of the device. The dominant rGO and minor NiS phase exist in the composite. The morphology of the composite is white strips rGO and NiS agglomerate particle. The element of C, O, Ni and S present in the composite. The highest g of 1.04% and Jsc of 7.39 mA cm(cid:1)2 were obtained from the device with 0.06 M NiCl2 resulted from the longest carrier lifetime. The photovoltaic parameters results reveal that NiS-rGO composite has potential to become as a free platinum counter electrode of DSSC.

    关键词： Reduced graphene oxide,Dye-sensitized solar cells,Nickel sulphide,Counter electrode

    更新于2025-09-23 15:19:57

  • Efficient phenothiazine-ruthenium sensitizers with high open-circuit voltage (Voc) for high performance dye-sensitized solar cells

    摘要： Herein, we designed and synthesized two highly effective phenothiazine-ruthenium sensitizers JR1 and JR2 to use in dye-sensitized solar cells. The structure of N719 was further optimized, 1,10-phenanthroline modified by phenothiazine was used instead of 2,2'-bipyridine-4,4'-dicarboxylic acid to as the electron donor. Compared with N719, these two ruthenium dyes show better optical properties, both the spectral response range and the molar absorption coefficient of dye molecules have been significantly improved. The IPCE response of JR1 is obviously improved, the response range of photocurrent is widened to 800 nm, the overall response value is also higher. JR2 shows the widest and highest IPCE response curve, in the region of 410-600 nm, the IPCE value of JR2 is more than 70%, and at 530 nm, the IPCE value has reached 79%, so JR2 shows the highest Jsc of 17.18 mA cm-2. Further optimization of molecular structure not only improves the light-harvesting performance of the device, but also reduces the charge recombination behaviour and improves the the electron lifetime, so the Voc is greatly increased. Especially for JR2, the introduction of the second long carbon chain not only increases the solubility of the dye, but also further suppresses the dye aggregation and reduces the charge recombination. The phenothiazine-ruthenium dye JR2 shows a high Voc of 841 mV, while the theoretical Voc of DSSCs based on I-/I3 - electrolyte is about 900 mV. JR2 exhibits a superior PCE of 9.12%, which exceeds N719 (8.03%) about 14%.

    关键词： Phenothiazine,Ruthenium sensitizers,Dye-sensitized solar cells,Charge recombination

    更新于2025-09-23 15:19:57

  • A new electrochemically prepared composite counter electrode for dye-sensitized solar cells

    摘要： In this paper, we propose new counter electrodes for applications in dye-sensitized solar cells (DSSCs). Polyaniline (PANi), tungsten trioxide (WO3), and their composite are deposited on indium thin oxide substrates using cyclic voltammetry technique and employed as counter electrodes that reached comparable and superior performances than Pt counter electrodes. These excellent results are achieved due to the high conductivity and electrocatalytic behavior of the prepared materials. Morphological, electrocatalytic, bonding structure, charge transfer properties, and photovoltaic characteristics are respectively investigated by field emission electron microscopy, cyclic voltammetry, Tafel analysis, Fourier-transform infrared spectroscopy, UV-visible spectroscopy, energy dispersive spectroscopy, electrochemical impedance spectroscopy, and current-voltage analysis. Our best DSSC that is fabricated from the WO3/PANi nanocomposite counter electrode demonstrated an efficiency of 6.78%, which is a 12.4% improvement in comparison with the Pt-based DSSC.

    关键词： Counter electrode,Tungsten trioxide,Cyclic voltammetry,Composites,Dye-sensitized solar cells,Polyaniline

    更新于2025-09-23 15:19:57

  • Liquid State and Zombie Dye Sensitized Solar Cells with Copper Bipyridine Complexes Functionalized with Alkoxy Groups

    摘要： Copper redox mediators can be employed in dye sensitized solar cells (DSCs) both as liquid electrolyte or as solid state hole transport materials (HTMs). The solid state devices, employing copper complex HTMs can be simply obtained by solvent evaporation in liquid state devices. During this evolution, the copper complex molecules present in the electrolyte solvent slowly aggregate in the pores of the TiO2 film and they also close the gap between the TiO2 film and counter electrode. However, the crystallization of the HTM infiltrated in the mesoscopic TiO2 pores can lead to low photovoltaic performance. In order to prevent this problem, we designed two copper redox mediators [Cu(beto)2]1+ (beto=4,4’-diethoxy-6.6’-dimethyl-2,2’-bipyridine) and [Cu(beto2Ox)2]1+ (beto2Ox=4,4’-bis(2-methoxyethoxy)-6,6’-dimethyl-2,2’-bipyridine) with extended side chains. Firstly, we studied these complexes in liquid state devices in reference to the [Cu(tmby)2]2+/1+ complex (tmby = 4,4?,6,6?- tetramethyl-2,2?-bipyridine). The solar-to-electrical power conversion efficiencies for liquid state devices, were over 10% for all of the complexes by using the organic Y123 dye under 1000 Wm-2 AM1.5G illumination. However, solid state devices showed significantly diminished charge transport properties and short circuit current density values even though the crystallization is reduced.

    关键词： Hole transport materials,Dye sensitized solar cells,Crystallization,Photovoltaic performance,Copper redox mediators

    更新于2025-09-23 15:19:57

  • Investigation of the photovoltaic performance of dye-sensitized solar cells utilizing 9,9'-bianthracene-based dyes as a co-sensitizer

    摘要： In this paper, we report two interesting metal-free organic co-sensitizers, which use fluorene or carbazole as the donor scaffold and are linked to cyanoacrylic acid via a 9,9′-bianthrylene π-spacer. These organic dyes have a particular twisted structure, and their absorption spectra are complementary to the leading dye MK–3. We investigated the photophysical, electrochemical, and photovoltaic properties of these two co-sensitizers in detail. Interestingly, when the same concentration of MK–3 dye was co-sensitized with different concentrations of LD2, the performance of the devices did not show a linear change, and the best photovoltaic performance was obtained with sensitized device made with 0.2 mM MK–3 and 0.04 mM LD2. It displayed the power conversion efficiency (PCE) of 6.47 % with short-circuit current density (Jsc) of 14.54 mA cm?2, open-circuit voltage (Voc) of 0.653 V and fill factor (FF) of 0.681. These results provide a reference for the optimization of the device by the method of co-sensitization; that is, selecting a suitable co-sensitizer at a suitable concentration may be one of the crucial factors.

    关键词： Co-sensitization,Molecular aggregation,9,9'-Bianthracene,Dye-sensitized solar cells

    更新于2025-09-23 15:19:57

  • Enhanced Power Conversion Efficiency of Dye-Sensitized Solar Cells by Band Edge Shift of TiO2 Photoanode

    摘要： By simple soaking titanium dioxide (TiO2) films in an aqueous Na2S solution, we could prepare surface-modified photoanodes for application to dye-sensitized solar cells (DSSCs). An improvement in both the open-circuit voltage (Voc) and the fill factor (FF) was observed in the DSSC with the 5 min-soaked photoanode, compared with those of the control cell without any modification. The UV–visible absorbance spectra, UPS valence band spectra, and dark current measurements revealed that the Na2S modification led to the formation of anions on the TiO2 surface, and thereby shifted the conduction band edge of TiO2 in the negative (upward) direction, inducing an increase of 29 mV in the Voc. It was also found that the increased FF value in the surface-treated device was attributed to an elevation in the shunt resistance.

    关键词： surface modification,conduction band edge shift,dye-sensitized solar cell,sodium sulfide

    更新于2025-09-23 15:19:57

  • Digital printing of efficient dye-sensitized solar cells (DSSCs)

    摘要： This study reports on the printing of TiO2 nanoparticles and the sensitization of the photoanode by a new digital printing technology, named Digital Materials Deposition “DMD” to fabricate semi-transparent DSSCs. In this study, the push-pull dye coded “D35” and I3?/I? were used respectively as sensitizer and redox mediator. The photovoltaic performances of the solar cells printed with the DMD technology were compared to those prepared by the conventional method consisting of screen-printed nanoparticles and dying process by overnight soaking of the electrode into a solution of the sensitizer. Scanning Electron Microscopy shows that the DMD printed ?lm is more porous than the one deposited by screen printing. The cells prepared by DMD give higher solar energy conversion e?ciency (Jsc = 12.65 mA/cm2, Voc = 775 mV, FF = 75%, PEC = 7.4%) than with conventional screen-printing technique (Jsc = 10.03 mA/cm2, Voc = 760 mV, FF = 72%, PEC = 5.48%). IMVS/IMPS measurements demonstrate that the superior photocurrent density delivered by DMD printed solar cells is due to a higher charge collection e?ciency. Overall, this study demonstrates that DMD technology simpli?es the DSSC fabrication process with a reduction of the material consumption and it is quick and e?cient representing an innovative and attractive method to manufacture DSSCs.

    关键词： Semi-transparent,Fast fabrication process,Dye-sensitized solar cells,Digital printing

    更新于2025-09-23 15:19:57