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1.
A star-shaped electron acceptor with porphyrin as core and rhodanine-benzothiadiazole as end groups linked with ethynyl units was developed for non-fullerene solar cells, in which a PCE of 1.9% with broad photo response was achieved when combining with a diketopyrrolopyrrole-polymer as electron donor.  相似文献   

2.
Tandem-junction organic solar cells require solar cells with visible light photo-response as front cells, in which an open-circuit voltage (Voc) above 1.0 V is highly demanded. In this work, we are able to develop electron acceptors to fabricate non-fullerene organic solar cells (NFOSCs) with a very high Voc of 1.14 V. This was realized by designing perylene bisimide (PBI)-based conjugated materials fused with benzodithiophene, in which Cl and S atom were introduced into the molecules in order to lower the frontier energy levels. The fused structures can reduce the aggregation of PBI unit and meanwhile maintain a good charge transport property. The new electron acceptors were applied into NFOSCs by using Cl and S substituted conjugated polymers as electron donor, in which an initial power conversion efficiency of 6.63 % and a high Voc of 1.14 V could be obtained. The results demonstrate that the molecular design by incorporating Cl and S atom into electron acceptors has great potential to realize high performance NFOSCs.  相似文献   

3.
New efficient push–pull organic semiconductors comprising of the bis(9,9-dimethyl-9H-fluoren-2-yl)aniline (bisDMFA) donor and the various acceptors such as NO2, DCBP, and TCF, which were linked with bithiophene or vinyl bithiophene π-conjugation bridges, were synthesized, and their photovoltaic characteristics were investigated in solution-processed small molecule organic solar cells (SMOSCs). The intramolecular charge transfers of these materials were effectively appeared in between bisDMFA donor and acceptors, depending on the electron-withdrawing strength of acceptors. The organic semiconductors having NO2 and DCBP acceptors exhibited the most efficient photovoltaic performance, showing power conversion efficiency (PCE) of 1.98% (±0.17) and 2.01% (±0.21), respectively. When the TiOx thin layer was treated on photoactive layer, the organic semiconductor having NO2 showed the best PCE of 2.70% with short circuit current of 8.19 mA/cm2, fill factor of 0.40, and open circuit voltage of 0.83 V in SMOSC devices.  相似文献   

4.
Enhancement of the quinoidal character on fused-ring small molecule acceptor by introducing polarizable thiophene effectively reduces the optical band gap and enhances the near IR absorptivity, giving rise to improved short-circuit current and fill-factor.  相似文献   

5.
We present a new photosensitizer – Ag2S quantum dots (QDs) – for solar cells. The QDs were grown by the successive ionic layer adsorption and reaction deposition method. The assembled Ag2S-QD solar cells yield a best power conversion efficiency of 1.70% and a short-circuit current of 1.54 mA/cm2 under 10.8% sun. The solar cells have a maximal external quantum efficiency (EQE) of 50% at λ = 530 nm and an average EQE of ~ 42% over the spectral range of 400–1000 nm. The effective photovoltaic range covers the visible and near-infrared spectral regions and is ~ 2–4 times broader than that of the cadmium chalcogenide systems — CdS and CdSe. The results show that Ag2S QDs can be used as a highly efficient and broadband sensitizer for solar cells.  相似文献   

6.
Several multinuclear ferrocenyl–ethynyl complexes of formula [(η5-C5H5)(dppe)MII?CC–(fc)n–CC–MII(dppe)(η5-C5H5)] (fc = ferrocenyl; dppe = Ph2PCH2CH2PPh2; 1: MII = Ru2+, n = 1; 2: MII = Ru2+, n = 2; 3: MII = Ru2+, n = 3; 4: MII = Fe2+, n = 2; 5: MII = Fe2+, n = 3) were studied. Structural determinations of 2 and 4 confirm the ferrocenyl group directly linked to the ethynyl linkage which is linked to the pseudo-octahedral [(η5-C5H5)(dppe)M] metal center. Complexes of 15 undergo sequential reversible oxidation events from 0.0 V to 1.0 V referred to the Ag/AgCl electrode in anhydrous CH2Cl2 solution and the low-potential waves have been assigned to the end-capped metallic centers. The solid-state and solution-state electronic configurations in the resulting oxidation products of [1]+ and [2]2+ were characterized by IR, X-band EPR spectroscopy, and UV–Vis at room temperature and 77 K. In [1]+ and [2]2+, broad intervalence transition band near 1600 nm is assigned to the intervalence transition involving photo-induced electron transfer between the Ru3+ and Fe2+ metal centers, indicating the existence of strong metal-to-metal interaction. Application of Hush’s theoretical analysis of intervalence transition band to determine the nature and magnitude of the electronic coupling between the metal sites in complexes [1]+ and [2]2+ is also reported. Computational calculations reveal that the ferrocenyl–ethynyl-based orbitals do mix significantly with the (η5-C5H5)(dppe)Ru metallic orbitals. It clearly appears from this work that the ferrocenyl–ethynyl spacers strongly contribute in propagating electron delocalization.  相似文献   

7.
Two novel trialkylsilyl-containing organic sensitizers (JK-53 and JK-54) have been designed and synthesized. Nanocrystalline TiO2–silica-based dye-sensitized solar cells (DSSCs) were fabricated using these dyes. Under standard global AM 1.5 solar conditions, the JK-53-sensitized cell gave a short-circuit photocurrent density (Jsc) of 6.37 mA cm?2, an open-circuit voltage (Voc) of 0.70 V, and a fill factor of 0.74. These values correspond to an overall conversion efficiency (η) of 3.31%. By comparison, the JK-54-sensitized cell resulted in a Jsc of 7.52 mA cm?2, a Voc of 0.71 V, and a fill factor of 0.75. These values give an overall conversion efficiency of 4.01%.  相似文献   

8.
Diverse fused thiophenes with electron-rich and electron-deficient blocks have been synthesized and employed as the π-conjugated spacers of organic dyes for the dye-sensitized solar cells (DSSCs). The effects of these fused thiophenes were investigated by their absorption spectra, electrochemical and photovoltaic properties. For a typical device a maximum power conversion efficiency of 6.11% was obtained under simulated AM 1.5 irradiation (100 mW cm?2): a short-circuit current (JSC) of 14.47 mA cm?2, an open-circuit voltage (VOC) of 670 mV, and a fill factor (FF) of 0.63.  相似文献   

9.
Solar cells were fabricated using novel bubble-like CdSe nanoclusters sensitized highly ordered titanium oxide nanotube (TiO2 NT) array, prepared by anodization technique. The CdSe sensitization of TiO2 NT arrays was carried out by a chemical bath deposition method with freshly prepared sodium selenosufite, ammonium hydroxide and cadmium acetate dehydrate at different deposition times: 20, 40 and 60 min. The adsorption of CdSe nanoclusters on the upper and inner surface of the TiO2 NT arrays has been confirmed by field emission scanning electron and transmission electron microscopes. The results show the variation in cell a performance with different deposition times (20, 40, and 60 min) of CdSe on TiO2 NT arrays. The solar cell with CdSe, deposited for 60 min, shows reasonably high photovoltaic property compared to the reported results of similar studies. This solar cell shows the maximum photoelectric conversion efficiency of 1.56% (photocurrent of 7.19 mA/cm2; photovoltage of 0.438 V; and fill factor of 49.5%) and average incident photon to current efficiency of 50.2%. The photocurrent, incident photon-current efficiency and electron lifetime have been improved due to the increase of covered area and size of bubble-like CdSe nanoclusters on TiO2 NT arrays with the increase of deposition time.  相似文献   

10.
This paper reports on the application of cornstalks-derived high-surface-area microporous carbon (MC) as the efficient photocathode of dye-sensitized solar cells (DSCs). The photocathode, which contains MC active material, Vulcan XC–72 carbon black conductive agent, and TiO2 binder, was obtained by a doctor blade method. Electronic impedance spectroscopy (EIS) of the MC film uniformly coated on fluorine doped SnO2 (FTO) glass displayed a low charge-transfer resistance of 1.32 Ω cm2. Cyclic voltammetry (CV) analysis of the as-prepared MC film exhibited excellent catalytic activity for I3?/I? redox reactions. The DSCs assembled with the MC film photocathode presented a short-circuit photocurrent density (Jsc) of 14.8 mA cm?2, an open-circuit photovoltage (Voc) of 798 mV, and a fill factor (FF) of 62.3%, corresponding to an overall conversion efficiency of 7.36% under AM 1.5 irradiation (100 mW cm?2), which is comparable to that of DSCs with Pt photocathode obtained by conventional thermal decomposition.  相似文献   

11.
Spectroscopic studies revealed that the interaction of cimetidine drug with electron acceptors iodine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) resulted through the initial formation of ionic intermediate to charge transfer (CT) complex. The CT-complexes of the interactions have been characterized using UV–vis, 1H NMR, FT-IR and GC–MS techniques. The formation of triiodide ion, I3?, is further confirmed by the observation of the characteristic bands in the far IR spectrum for non-linear I3? ion with Cs symmetry at 156 and 131 cm?1 assigned to νas(I–I) and νs(I–I) of the I–I bond and at 73 cm?1 due to bending δ(I3?). The rate of formation of the CT-complexes has been measured and discussed as a function of relative permittivity of solvent and temperature. The influence of relative permittivity of the medium on the rate indicated that the intermediate is more polar than the reactants and this observation was further supported by spectral studies. Based on the spectroscopic results plausible mechanisms for the interaction of the drug with the chosen acceptors were proposed and discussed and the point of attachment of the multifunctional cimetidine drug with these acceptors during the formation of CT-complex has been established.  相似文献   

12.
In this paper, luminescence properties of orthovanadates, Y1−xyGdxVO4:ySm3+ (where x = 0.05–0.50, y = 0.01–0.05), and the energy transfer mechanism from VO43− to Sm3+ via Gd3+ ions were investigated in detail. X-ray diffraction (XRD) analysis confirmed the crystalline phase for synthesized nanophosphor in a tetragonal structure with I41/amd space group. The average crystallite size estimated from XRD was ∼28 nm. Field-emission scanning electron microscopy coupled with energy dispersive X-ray analysis revealed oval shaped morphology and composition of the nanophosphor, respectively. From high-resolution transmission electron microscopy observations, the particle sizes were found to be in the range 10–80 nm. The photoluminescence studies of Y0.77Gd0.20VO4:0.03Sm3+ nanophosphor under 311 nm excitation exhibits dominant emission peak at 598 nm corresponding to 4G5/2  6H7/2 transition. The energy transfer occurs from VO43− to Sm3+ via Gd3+ ions was confirmed by applying Dexter and Reisfeld’s theory and Inokuti-Hirayama model. Moreover, the energy transfer efficiencies and probabilities were calculated from the decay curves. Furthermore, Commission Internationale de l’Eclairage (CIE) color coordinate (0.59, 0.37) has been observed to be in the orange-red (598 nm) region for Y0.77Gd0.20VO4:0.03Sm3+ nanophosphor. These results perfectly established the suitability of these nanophosphors in improving the efficiency of silicon solar cells, light emitting diodes, semiconductor photophysics, and nanodevices.  相似文献   

13.
TiO2 has been widely utilized for various industrial applications such as photochemical cells, photocatalysts, and electrochromic devices. The crystallinity and morphology of TiO2 films play a significant role in determining the overall efficiency of dye-sensitized solar cells (DSSCs). In this study, the preparation of nanostructured TiO2 films by electron beam irradiation and their characterization were investigated for the application of DSSCs. TiO2 films were exposed to 20–100 kGy of electron beam irradiation using 1.14 MeV energy acceleration with a 7.46 mA beam current and 10 kGy/pass dose rates. These samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS) analysis. After irradiation, each TiO2 film was tested as a DSSC. At low doses of electron beam irradiation (20 kGy), the energy conversion efficiency of the film was approximately 4.0% under illumination of simulated sunlight with AM 1.5 G (100 mW/cm2). We found that electron beam irradiation resulted in surface modification of the TiO2 films, which could explain the observed increase in the conversion efficiency in irradiated versus non-irradiated films.  相似文献   

14.
A polyaniline-modified screen-printed carbon electrode (PANI/SPCE) was prepared by electropolymerization for the construction of a novel disposable cell impedance sensor. The conductive polymer improved greatly the electron transfer of SPCE and was very effective for cell immobilization. The adhesion of cells increased the electron transfer resistance (Ret) of redox probe on the PANI/SPCE surface, producing an impedance sensor for K562 leukaemia cells with a semilogarithm linear range from 104 to 107 cells ml−1 and a limit of detection of 8.32 × 103 cells ml−1 at 10σ. The proliferation of cells on the conductive polymer increased the Ret, leading to a novel way to monitor the growth process of cells on the PANI/SPCE. The electrochemical monitoring indicated K562 leukaemia cells cultured in vitro on the PANI surface were viable for 60 h, consistent with the analysis from microscopic imaging and MTT assay. This method for monitoring the surface proliferation and detecting the number of viable cells was simple, low-cost and disposable, thus providing a convenient avenue for electrochemical study of cell immobilization, adhesion, proliferation and apoptosis.  相似文献   

15.
Poly (neutral red) nanowires (PNRNWs) have been synthesized for the first time by the method of cyclic voltammetric electrodeposition using porous anodic aluminum oxide (AAO) template and were examined by scanning electron microscopy (SEM) and transmission electron microscope (TEM). Moreover, horseradish peroxidase (HRP) was encapsulated in situ in PNRNWs (denoted as PNRNWs–HRP) by electrochemical copolymerization for potential biosensor applications. The PNRNWs showed excellent efficiency of electron transfer between the HRP and the glassy carbon (GC) electrode for the reduction of H2O2 and the PNRNWs–HRP modified GC electrode showed to be excellent amperometric sensors for H2O2 at −0.1 V with a linear response range of 1 μM to 8 mM with a correlation coefficient of 0.996. The detection limit (S/N = 3) and the response time were determined to be 1 μM and <5 s and the high sensitivity is up to 318 μA mM−1 cm−2.  相似文献   

16.
Two new triphenylamine-based metal-free organic dyes (TPTDYE-1 and TPTDYE-2) containing 1-(2,6-diisopropylphenyl)-2,5-di(2-thienyl)pyrrole as a new π-conjugated chromophore were synthesized for dye-sensitized solar cell (DSSC) applications. TPTDYE-1 containing three donor groups around the acceptor group was found to show relatively narrow absorption band from 300 nm to 470 nm while TPTDYE-2 having extended π–π delocalization between the donor and acceptor group showed broad absorption band from 300 nm to 550 nm. The electrochemical studies indicate that the HOMO–LUMO energy gap of TPTDYE-1 is considerably wider than that of TPTDYE-2. The dye-sensitized solar cell performance of each dye was investigated, and the TPTDYE-2-sensitized cell was found to show a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 75%, a short-circuit photocurrent density (Jsc) of 13.50 mA/cm2, an open-circuit voltage (Voc) of 0.72 V, and a fill factor (FF) of 0.69, corresponding to an overall conversion efficiency of 6.71% under simulated AM 1.5 irradiation (100 mW/cm2). Under the same condition the TPTDYE-1-sensitized cell showed the same IPCE value of 75% with a promising conversion efficiency of 6.00%, a Jsc of 11.11 mA/cm2, a Voc of 0.76 V, and a FF of 0.71.  相似文献   

17.
Transparent glasses, melt quenching derived, containing 10RO·20Bi2O3·(70 ? x)B2O3·xTiO2 [R = Ca, Sr] with x = 0, 0.5, 1.0 wt% were characterized by X-ray powder diffraction. Physical and spectroscopic properties viz., density, absorption, emission, electron paramagnetic resonance (EPR) and FTIR were investigated. The absorption band around 823 nm in pure glass samples is attributed to the electronic transition of 3P0 to 3P2 of Bi+ radicals. A small absorption hump centered around 609 nm is found in all doped glasses due to 2T2g to 2Eg transition of octahedral Ti3+ ions. The emission results revealed that all the samples exhibit a broad emission band covering entire visible-light range, with λex = 360 nm, centered 470–520 nm corresponds to electronic transition of 3P1 to 1S0 of Bi3+ ions, therefore the present materials can be potentially used as tunable or full-color display systems. And a strong emission around 706 nm with λex = 514 nm due to transition of 2P3/2 to 2P1/2 of Bi2+ ions. In SrO mixed glasses Ti4+ ions effect the environment of Bi3+ ion symmetry units from C2 to C3i. A small EPR signal (at room temperature) is observed in titanium doped glasses due to Ti3+ ions. In both the series with increase of TiO2 concentration BO4 units are gradually converted into BO3 units and new cross linkages are formed, like B–O–Ti, Bi–O–Ti at the expense of B–O–B bonds.  相似文献   

18.
The phosphate mineral series eosphorite–childrenite–(Mn,Fe)Al(PO4)(OH)2·(H2O) has been studied using a combination of electron probe analysis and vibrational spectroscopy. Eosphorite is the manganese rich mineral with lower iron content in comparison with the childrenite which has higher iron and lower manganese content. The determined formulae of the two studied minerals are: (Mn0.72,Fe0.13,Ca0.01)(Al)1.04(PO4, OHPO3)1.07(OH1.89,F0.02)·0.94(H2O) for SAA-090 and (Fe0.49,Mn0.35,Mg0.06,Ca0.04)(Al)1.03(PO4, OHPO3)1.05(OH)1.90·0.95(H2O) for SAA-072. Raman spectroscopy enabled the observation of bands at 970 cm−1 and 1011 cm−1 assigned to monohydrogen phosphate, phosphate and dihydrogen phosphate units. Differences are observed in the area of the peaks between the two eosphorite minerals. Raman bands at 562 cm−1, 595 cm−1, and 608 cm−1 are assigned to the ν4 bending modes of the PO4, HPO4 and H2PO4 units; Raman bands at 405 cm−1, 427 cm−1 and 466 cm−1 are attributed to the ν2 modes of these units. Raman bands of the hydroxyl and water stretching modes are observed. Vibrational spectroscopy enabled details of the molecular structure of the eosphorite mineral series to be determined.  相似文献   

19.
Redox-active polymers composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) and redox-active units are a new category of cytocompatible electron mediators which possess permeability of cell membranes. However, supply of electrons to living cells through the cytocompatible redox polymers has not been achieved so far due to the high redox potential of the redox polymers. Here we report that electrons were successfully supplied from a cathode into Escherichia coli cells, generating the current density of 7.8 μA cm 2 at − 0.40 V vs. SHE. It was also revealed that the cytocompatibility of viologen was improved simply by co-polymerization with MPC.  相似文献   

20.
In order to absorb a broad spectrum in visible region, a co-sensitized TiO2 electrode was prepared by CdSe and Mg-doped CdSe quantum dots (Q dots). The power conversion efficiency of the co-sensitized Q dots photoelectrochemical solar cells (PECs) showed 1.03% under air mass 1.5 condition (I = 100 mW/cm2), which is higher than that of individual Q dots-sensitized PECs. The incident-photon-to-current conversion efficiency of the co-sensitized PECs showed absorption peaks at 541 and 578 nm corresponding to the two Q dots and displayed a broad spectral response over the entire visible spectrum in the 500–600 nm wavelength domains.  相似文献   

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