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Solar cells sensitized with porphyrin dyes with a carbazole donor: The effects of an auxiliary benzothiadiazole acceptor and bulky substituents on the donor
摘要： Three porphyrin sensitizers XW54–XW56 containing a carbazole donor have been designed and synthesized by introducing a benzothiadiazole (BTD) unit as the auxiliary electron acceptor to extend the absorption spectra and/or bulky dihexyloxyphenyl groups into the carbazole unit to suppress dye aggregation and improve the photovoltage (Voc). The BTD unit incorporated in XW54 obviously broadens and red-shifts the absorption threshold to ca. 700 nm, as compared with that of 650 nm observed for XW1. Thus, XW54 exhibits a much broader monochromatic photon-to-electron conversion efficiency (IPCE) spectrum with an extremely red-shifted onset wavelength of 780 nm, resulting in a photocurrent density (Jsc) of 11.60 mA cm?2, higher than that of XW1. Unfortunately, the Voc value was decreased owing to the more severe dye aggregation caused by the large conjugation framework induced by the presence of the BTD unit. As a result, XW54 shows an efficiency of 6.26%, slightly higher than that of 6.11% obtained for XW1. On the other hand, with the bulky dihexyloxyphenyl donor groups introduced to XW55, a highest Voc of 860 mV was achieved, which can be ascribed to the efficient prevention of charge recombination and suppression of dye aggregation. Thus, XW55-based cells exhibit an improved e?ciency of 6.60%. On the basis of XW54 and XW55, two bulky dihexyloxyphenyl groups and a BTD unit were simultaneously introduced to XW56, affording a highest efficiency of 7.03%, with the Jsc and Voc values of 12.5 mA cm?2 and 785 mV, respectively. These results compose a novel approach for developing e?cient dye-sensitized solar cells (DSSCs) by simultaneously introducing bulky dihexyloxyphenyl groups and a benzothiadiazole unit, which may synergistically broaden the absorption spectra and suppress the dye aggregation, resulting in improved photocurrent and photovoltage.
关键词： Dye-sensitized solar cells,Sensitizers,Porphyrin,Bulky groups,Carbazole
更新于2025-11-19 16:56:42
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Enantioselective Visible Light-mediated Formation of 3-Cyclopropylquinolones via Triplet-sensitized Deracemization
摘要： 3-Allyl-substituted quinolones undergo a triplet-sensitized di-π-methane rearrangement to the corresponding 3-cyclopropylquinolones upon irradiation with visible light (λ = 420 nm). A chiral hydrogen bonding sensitizer (10 mol%) was shown to promote the reaction enantioselectively (88-96% yield, 32-55% ee). Surprisingly, it was found that the enantiodifferentiation does not occur at the state of initial product formation but that it is the result of a deracemization event. The individual parameters that control the distribution of enantiomers in the photostationary state have been identified.
关键词： enantioselectivity,small ring systems,photochemistry,hydrogen bonds,sensitizers,chiral resolution
更新于2025-09-23 15:22:29
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Theoretical studies on D-A-??-A and D-(A-??-A)2 dyes with thiophene-based acceptor for high performance p-type dye-sensitized solar cells
摘要： Eight p-type dyes with D-A-π-A or D-(A-π-A)2 structures were designed to investigate the effect of thiophene derivatives acting as acceptors on the properties of the sensitizers. Structure optimizations were performed by the density functional theory (DFT) method, and the electronic and absorption characters were obtained with the time-dependent DFT (TD-DFT). The results show that all the eight dyes have an excellent light harvesting efficiency (LHE) performance (0.99–1.00). And the driving forces of hole injection (ΔGinj) and dye regeneration (ΔGreg) of all dyes are more negative than (cid:0) 0.2 eV, resulting in an efficient hole injection and dye regeneration. Furthermore, the dyes with 2,3-dimethylpyrazine thiophene moiety (DMPZT-1) have the narrowest energy gaps. Importantly, the dyes with DMPZT-1 moiety display red shifts of the UV–vis absorption and enhanced absorptions of visible light (400–800 nm) in comparison to their prototype. In addition, the charge recombination (ΔGCR) performance of A1 and B1 is improved by DMPZT-1. Compared with the D-A-π-A dyes, the additional -A-π-A chain in D-(A-π-A)2 could decrease energy gap further and improve the visible light adsorption, LHE, and driving forces for hole injection and charge regeneration (ΔGinj and ΔGreg). Replacing thiophene with DMPZT-1 acceptor is an effective way to improve the performance of the dyes.
关键词： DFT,p-type organic sensitizers,DSSCs,D-A-π-A,Thiophene derivatives
更新于2025-09-23 15:21:01
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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
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Phenanthrenea??Fuseda??Quinoxaline as Key Building Block for Highly Efficient and Stable Sensitizers in Copper Electrolyte Based Dyea??Sensitized Solar Cells
摘要： Dye-sensitized solar cells (DSSCs) based on Cu(II/I) bipyridyl or phenanthroline complexes as redox shuttles have achieved very high open-circuit voltages (VOC, > 1 V). However, their short-circuit photocurrent density (JSC) has remained modest. The challenge for increasing the JSC is expected to extend the spectral response of sensitizers to the red or NIR region while maintaining efficient electron injection in the mesoscopic TiO2 film and fast regeneration by the Cu(I) complex. Here, we report two new D-A-π-A featured sensitizers coded HY63 and HY64, which employ either benzothiadiazole (BT) or phenanthrene-fused-quinoxaline (PFQ) as the auxiliary electron-withdrawing acceptor moiety. In spite of very similar energy levels and absorption onsets, HY64-based DSSCs outperform largely their HY63 counterpart, achieving an outstanding power conversion efficiency (PCE) of 12.5% with superior stability. In depth studies of interfacial charge carrier dynamics show that PFQ is superior to BT in retarding charge recombination resulting in near quantitative collection of photogenerated charge carriers.
关键词： sensitizers,light-harvesting,dye-sensitized solar cells,copper redox shuttle,charge recombination
更新于2025-09-23 15:19:57
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Nanoscale Perovskite-Sensitized Solar Cell Revisited: Is This Dye-Cell or Perovskite-Cell?
摘要： A general and straightforward way of preparing few nanometer-sized well-separated MAPbIxBr3-x perovskite photosensitizers on the surface of ~1 μm thick mesoporous TiO2 photoanode was suggested via a two-step sequential deposition of low-concentrated lead halides (0.10 ~ 0.30 M PbI2 or PbBr2) and methylammonium iodide/bromide (MAI/MABr). When those nanoscale MAPbIxBr3-x perovskites are incorporated as a photosensitizer in typical solid state dye-sensitized solar cells (ss-DSSCs), it could be verified clearly by the capacitance analysis that nano-particulate MAPbI3 perovskites are playing the same role as that of a typical dye sensitizer (MK-2 molecule) though their size, composition and structure are different.
关键词： perovskites,Impedance analysis,solid state dye-sensitized solar cells,sensitizers,nanostructures
更新于2025-09-23 15:19:57
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Design, Molecular Modeling and Synthesis of Metal-Free Sensitizers of Thieno Pyridine Dyes as Light-Harvesting Materials with Efficiency Improvement Using Plasmonic Nanoparticles
摘要： Considering the thiophene unit as an electron-rich heterocycle, it is investigated with the aim of elucidating its potential efficiency for solar cell application. With the introduction of active substituents such as COOEt, CONH2 and CN into the thiophene segment, three novel thieno pyridine sensitizers (6a–c), based on donor-acceptor D-π-A construction, are designed and synthesized. The effect of the anchoring groups is investigated based on their molecular orbital’s (MO’s) energy gap (Eg). The electrostatic interaction between the synthesized dyes and metal nanoparticles, namely gold, silver and ruthenium, is believed to improve their performance as organic sensitizers. The dye-sensitized solar cells (DSSCs) are manufactured using the novel diazenyl pyridothiophene dyes, along with their metal nanoparticles conjugates as sensitizers, and were examined for efficiency improvement. Accordingly, using this modification, the photovoltaic performance was significantly improved. The promising results of conjugate (6b/AgNPs), compared with reported organic and natural sensitizers (JSC (1.136 × 10?1 mA/cm2), VOC (0.436 V), FF (0.57) and η (2.82 × 10?2%)), are attributed to the good interaction between the amide, methyl, amino and cyano groups attached to the thiophene pyridyl scaffolds and the surface of TiO2 porous film. Implementation of a molecular modeling study is performed to predict the ability of the thiophene moiety to be used in solar cell applications.
关键词： metal nanoparticle,plasmonic,organic sensitizers,tetrahydrobenzothiophenes,dye-sensitized solar cells,thienopyridine,HOMO-LUMO
更新于2025-09-23 15:19:57
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Investigating Various Permutations of Copper Iodide/FeCu Tandem Materials as Electrodes for Dye-Sensitized Solar Cells with a Natural Dye
摘要： This work presents the synthesis and deposition of CuI and FeCu materials on copper substrates for dye-sensitized solar cell applications. FeCu is a metastable alloy of iron and copper powders and possesses good optical and intrinsic magnetic properties. Coupled with copper iodide as tandem layers, the deposition of these two materials was permutated over a pure copper substrate, characterized and then tested within a solar cell. The cell was sensitized with a natural dye extracted from a local desert plant (Calotropis Gigantea) and operated with an iodine/triiodide electrolyte. The results show that the best layer arrangement was Cu/FeCu/CuI, which gave an efficiency of around 0.763% (compared to 0.196% from reported cells in the literature using a natural sensitizer).
关键词： natural sensitizers,copper iodine,FeCu alloys,dye-sensitized solar cells,Calotropis Gigantea,ball milling
更新于2025-09-23 15:19:57
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Functionalized metal oxide nanoparticles for efficient dye-sensitized solar cells (DSSCs): A review
摘要： Dye-sensitized solar cells (DSSCs) are a next-generation photovoltaic energy conversion technology due to their low cost, ability to fabrication on various substrates, structural modifications, excellent transparency, photovoltaic output and its potential applications in wearable devices, energy sustainable buildings, solar-powered windows, etc. DSSC working devices consist of components such as conductive oxide substrates, photoanodes with wide bandgap semiconductors, dye molecules (sensitizers), counter electrodes and redox electrolytes, etc. High-efficiency DSSC devices can be fabricated suitable functionalization of semiconducting metal oxides with quantum dots, organic conjugated polymers, etc. In this review, we discuss different photovoltaic technologies, working principles of DSSCs, fabrication process of devices using various novel inorganic nanostructured materials, influencing parameters on the performance of DSC-device such as photoconversion efficiency (PCE), short circuit current (Jsc), open-circuit voltage (Voc) and fill factor (FF).
关键词： Photovoltaics,Quantum dots,Sensitizers,DSSC-device parameters,Dye-sensitized solar cells (DSSCs),Semiconducting metal oxides
更新于2025-09-23 15:19:57
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Phenanthrenea??Fuseda??Quinoxaline as Key Building Block for Highly Efficient and Stable Sensitizers in Copper Electrolyte Based Dyea??Sensitized Solar Cells
摘要： Dye-sensitized solar cells (DSSCs) based on Cu(II/I) bipyridyl or phenanthroline complexes as redox shuttles have achieved very high open-circuit voltages (VOC, > 1 V). However, their short-circuit photocurrent density (JSC) has remained modest. The challenge for increasing the JSC is expected to extend the spectral response of sensitizers to the red or NIR region while maintaining efficient electron injection in the mesoscopic TiO2 film and fast regeneration by the Cu(I) complex. Here, we report two new D-A-π-A featured sensitizers coded HY63 and HY64, which employ either benzothiadiazole (BT) or phenanthrene-fused-quinoxaline (PFQ) as the auxiliary electron-withdrawing acceptor moiety. In spite of very similar energy levels and absorption onsets, HY64-based DSSCs outperform largely their HY63 counterpart, achieving an outstanding power conversion efficiency (PCE) of 12.5% with superior stability. In depth studies of interfacial charge carrier dynamics show that PFQ is superior to BT in retarding charge recombination resulting in near quantitative collection of photogenerated charge carriers.
关键词： sensitizers,light-harvesting,dye-sensitized solar cells,copper redox shuttle,charge recombination
更新于2025-09-19 17:13:59