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MOF-derived ZnO as electron transport layer for improving light harvesting and electron extraction efficiency in perovskite solar cells
摘要： We adopt Metal-Organic-Framework (MOF)-derived zinc oxide (ZnO) as electron extraction material for hybrid cationic perovskite solar cells for the first time, breaking the prevailing paradigm of using oxides nanoparticle as electron extraction layer. MOF-derived ZnO with a polyhedral morphology and abundant internal porous structure can increase light harvesting ability and optimize the interfacial contact with perovskite. In contrast to conventional ZnO nanoparticles, the introduction of MOF-derived ZnO will achieve more efficient electron extraction, reduction of trapped state density and lower electron-hole recombination probability, thus significantly increase the fill factor and short-circuit current density of the cells. MOF-derived ZnO based perovskite solar cells exhibit a champion power conversion efficiency of 18.1% coupled with improved fill factor of 0.74 and short-circuit current density of 22.1 mA cm?2. Simultaneously, there is almost no hysteresis effect, and performance attenuation of the device in the ambient atmosphere over time can be suppressed. The performance improvement of perovskite solar cells stems from improved light harvesting efficiency in a wide wavelength range, as well as enhanced carrier extraction efficiency resulted from the increase of interface area between MOF-derived ZnO and perovskites.
关键词： MOF-Derived ZnO,Electron extraction,Perovskite solar cells,Light harvesting
更新于2025-09-16 10:30:52
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Resonance energy transfer-assisted random lasing in light-harvesting bio-antenna enhanced with a plasmonic local field
摘要： Thanks to the advent of the random laser, new light applications have opened up, ranging from biophotonic to security devices. Here, by using the well-known but unexplored light-harvesting bio-pigment of butterfly pea (Clitoria ternatea, CT) flower extract, generation of continuous-wave (CW) random lasing at ~660 nm has been demonstrated. Furthermore, a wavelength tunability of ~30 nm in the lasing emission was obtained by utilizing the resonance energy transfer (RET) mechanism in a gain medium with a binary mixture of CT extract and a commercially available methylene blue (MB) dye as the gain medium. In the CT extract–dye mixture, the bio-pigments are acting as donors and the MB dye molecules are acting as acceptors. Amplification in intensity of the lasing emission of this binary system has further been achieved in the presence of optimized concentrations of metal (Ag)–semiconductor (ZnO) scattering nanoparticles. Interestingly, the lasing threshold has been reduced from 128 to 25 W cm?2, with a narrowed emission peak just after loading of the Ag nanoplasmon in the ZnO-doped binary gain medium. Thanks to the strong localized electric field in the metal nanoplasmon, and the multiple scattering effects of ZnO, the lasing threshold was reduced by approximately four times compared to that of the gain medium without the use of scatterers. Thus, we believe that our findings on wavelength-tunable, non-toxic, biocompatible random lasing will open up new applications, including the design of low-cost biophotonic devices.
关键词： light-harvesting bio-antenna,resonance energy transfer,random laser,plasmonic local field,biocompatible
更新于2025-09-16 10:30:52
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The molecular mechanisms of light adaption in light-harvesting complexes of purple bacteria revealed by a multiscale modeling
摘要： The light-harvesting in photosynthetic purple bacteria can be tuned in response to the light conditions during cell growth. One of the used strategies is to change the energy of the excitons in the major light-harvesting complex, commonly known as LH2. In the present study we report the first systematic investigation of the microscopic origin of the exciton tuning using three complexes, namely the common (high-light) and the low-light forms of LH2 from Rps. acidophila plus a third complex analogous to the PucD complex from Rps. palustris. The study is based on the combination of classical molecular dynamics of each complex in a lipid membrane and excitonic calculations based on a multiscale quantum mechanics/molecular mechanics approach including a polarizable embedding. From the comparative analysis, it comes out that the mechanisms that govern the adaptation of the light conditions use the different H-bonding environment around the bacteriochlorophyll pigments to dynamically control both internal and inter-pigment degrees of freedom. While the former have a large effect on the site energies, the latter significantly change the electronic couplings, but only the combination of the two effects can fully reproduce the tuning of the final excitons and explain the observed spectroscopic differences.
关键词： purple bacteria,H-bonding environment,multiscale modeling,light-harvesting complexes,excitonic tuning
更新于2025-09-16 10:30:52
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Heteroaromatic rings as linkers for quercetin-based dye-sensitized solar cell applications: a TDDFT investigation
摘要： The electronic properties of quercetin (Q)–π–cyanoacrylic acid (CNA) dye molecules using heteroaromatic rings, namely cyclopentadiene (F1), furan (F2), pyrrole (F3), thiophene (F4), oxazole (F5), imidazole (F6), thiazole (F7), isoindene (FF1), benzofuran (FF2), indole (FF3), benzothiophene (FF4), benzoxazole (FF5), benzimidazole (FF6), and benzothiazole (FF7), as π-linkers are studied for the first time using Time-Dependent Density Functional Theory (TDDFT) with dimethyl sulfoxide (DMSO) as solvent to predict their excitation energy, absorption wavelength, oscillator strength, light harvesting efficiency, and exciton binding energy. The charge transfer and charge regeneration in the ground and excited states of the dyes are established. The photon to electron energy transfer from the dye (quercetin) to the semiconductor (TiO2) surface is analyzed based on intramolecular charge transfer. The results of the electron transfer studies on these newly designed dyes could be used to enhance the performance of resulting dye-sensitized solar cells.
关键词： Molecular orbital,Quercetin dye,Absorption spectra,Dye-sensitized solar cell,Light harvesting efficiency
更新于2025-09-16 10:30:52
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Barbier Hyperbranching Polymerization-Induced Emission toward Facile Fabrication of White LED and Light Harvesting Film
摘要： Luminescent polymers are generally constructed through polymerization of luminescent moieties. Polymerization itself however is mainly used for constructing polymer main chain and the importance of polymerization on luminescence has yet to be explored. Here, we demonstrate a polymerization-induced emission strategy producing luminescent polymers by introducing Barbier reaction to hyperbranching polymerization, which allows luminescent properties to be easily tuned from the traditional type to an aggregation-induced emission type by simply adjusting the monomer structure and the polymerization time. When rotation about the phenyl groups in hyperbranched polytriphenylmethanols (HPTPMs) is hindered, HPTPMs exhibit traditional emission property. When all phenyl groups of HPTPM are rotatable, i.e., p,p’,p’’-HPTPM, it exhibits interesting aggregation-induced emission property with tunable emission colors from blue to yellow, by just adjusting polymerization time. Further applications of aggregation-induced emission type luminescent polymers are illustrated by the facile fabrication of white LED and light harvesting film with an antenna effect greater than 14. This Barbier hyperbranching polymerization-induced emission provides a new strategy for the design of luminescent polymers, and expands the methodology and functionality library of both hyperbranching polymerization and luminescent polymers.
关键词： white LED,luminescent polymers,aggregation-induced emission,polymerization-induced emission,light harvesting film,Barbier hyperbranching polymerization
更新于2025-09-16 10:30:52
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N719 Derivatives for Application in a Dye-Sensitized Solar Cell (DSSC): A Theoretical Study
摘要： The primary goal of this investigation is to analyze the influence of the chemical modifications on the electronic structures of N719 derivatives for their use in Dye-Sensitized Solar Cells (DSSC), by employing Density Functional Theory (DFT). UV-Visible spectra indicate that the electronic configurations are essential to study the absorption of solar irradiation and to analyze the charge transport mechanism between the Electron Transport Layer (ETL), the electrolyte, and the dye. Open and closed-shell electronic configurations are related to the absorption and the excitation energies of the dye. According to the results reported here, it is possible to say that the best candidates are N719, N719-2, N719-7, and N719-8 (neutral and di-anionic). They may be used as useful dye sensitizers due to their bandgap and band alignment with the ETL, which contributes to having an effective charge transport during the functioning of the solar device. Another parameter that is reported in this investigation is the Light-Harvesting Efficiency (LHE) for all studied systems. This could help to improve the performance of the device since there is an increment in the generation of charge carriers. These results could be useful as a guide for experimental investigations on chemical modifications of these sensitizers.
关键词： UV-Visible Spectra,Light-Harvesting Efficiency,Molecular Structure,Spectroscopy,DFT,N719 Derivatives,Theoretical Study,Quantum Chemistry,Density Functional Theory,DSSC,Dye-Sensitized Solar Cell,LHE
更新于2025-09-12 10:27:22
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Se-Assisted Performance Enhancement of Cu <sub/>2</sub> ZnSn(S,Se) <sub/>4</sub> Quantum-Dot Sensitized Solar Cells via a Simple Yet Versatile Synthesis
摘要： The earth-abundant Cu2ZnSnS4 (CZTS) quantum dots (QDs) have emerged as one potential substitute to toxic cadmium or rare indium QDs, but their application in quantum dot-sensitized solar cells (QDSSCs) is still limited by the improper particle size and the rigorous synthesis and ligand exchange conditions. Herein, we developed a one-pot hot injection method by using Tri-n-octylphosphine oxide (TOPO) as the solvent and oleylamine as the capping agent to synthesize Cu2ZnSn(S,Se)4 (CZTSSe) QDs with adjustable size and narrow size distribution. The key feature of this approach is that we can take advantage of the high-temperature nucleation, low-temperature growth, and strong reducibility of NaHB4 to prepare small-sized CZTSSe QDs without using 1-dodecanethiol (DDT) and to extend the light harvesting range through Se incorporation. After Se incorporation, it turns out that the conduction band (CB) level of CZTSSe QDs decreases, implying that the injection driving force of the electron to the CB of TiO2 films becomes weaker and a larger recombination would be induced at the TiO2/QDs/electrolyte interface. Benefiting from the broadened optoelectronic response range, the induced higher Jsc (16.80 vs 14.13 mA/cm2) finally leads to the increase of the conversion efficiency of CZTSSe QDSSC from 3.17% to 3.54% without further modification. Despite the fact that the efficiency is still far behind those of literature reported values through use of other chalcogenide sensitizers, this DDT-free approach solves the main hindrance for the application of CZTSSe QDs in QDSSCs and holds a more convenient way for ligand exchange, light absorption improvement, and particle size control.
关键词： Cu2ZnSnS4,solar cells,Se incorporation,quantum dots,light harvesting
更新于2025-09-12 10:27:22
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Efficiency enhancement of pyridinium ylide dye-sensitized solar cells by introduction of benzothiadiazolyl chromophore: A computational study
摘要： Organic pyridinium ylide sensitizers NO108-NO111 with different anchoring groups show attractive applications in dye-sensitized solar cells. To elucidate the intrinsic sensitization mechanism of this series of dyes, theoretical calculations of electrochemical and spectroscopic properties for free and adsorbed ylides have been performed. Moreover, to prescreen and optimize suitable candidates for pyridinium ylide cells, the benzothiadiazole (BTD) group is introduced in the best-performing ylide NO111, and the afforded dye is coded as NO111-1. Comparing pyiridine-N-oxide in NO108, diethylmalonate in NO111 shows superior properties in terms of interfacial charge transfer, anti-aggregation, and long-term stability. It also demonstrates that the novel designed NO111-1-sensitized film possesses higher average theoretical maximum limit of short-circuit photocurrent density (≈ 23 mA/cm2), and slower parasitic recombination than NO111 one. This result is expected to further reveal the effects of anchoring groups on properties of dyes, and is helpful for the design of more efficient pyridinium ylide dyes.
关键词： Self-assembly,Pyridinium ylide dye,Anchoring group,Interfacial charge transfer,Light harvesting
更新于2025-09-12 10:27:22
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Expanding the Light-Harvesting of CsPbI2Br to Near-Infrared by Integrating with Organic Bulk-Heterojunction for Efficient and Stable Solar Cells
摘要： All-inorganic perovskite (CsPbX3, X=Br or I) solar cells demonstrate superior stability while the power conversion efficiency (PCE) lags behind the organic-inorganic hybrid counterparts mainly due to the limitation of narrow absorption bands. To broaden its absorption spectrum and improve its PCE, all-inorganic perovskite/organic integrated solar cells utilizing CsPbI2Br as ultraviolet-visible light absorber and PBDTTT-E-T:IEICO as near-infrared light absorber are demonstrated in this work. The integrated solar cells exhibit a broadened photo-response to over 900 nm attributing to the integration of PBDTTT-E-T:IEICO. The additional absorption enhances the short-circuit current density from 14.78 mA/cm2 to 15.98 mA/cm2, resulting greatly improved PCE of 14.03% for integrated solar cells, much higher than that of the control perovskite solar cells (12.53%) and organic solar cells (7.51%). In-depth understanding of the charge transfer dynamic process in CsPbI2Br/PBDTTT-E-T:IEICO film is comprehensively analyzed by photoinduced transient absorption spectroscopy. Furthermore, the air stability and thermal stability of the integrated solar cells are greatly enhanced. For unencapsulated integrated solar cells, the PCE still preserve 95% of its initial value after aging for 300 hours in an ambient environment and the PCE retains about 90% of its original value even after aged at 85 ℃ for 180 hours in nitrogen.
关键词： light-harvesting,perovskite solar cell,stability,all-inorganic perovskite,integrated solar cell
更新于2025-09-12 10:27:22
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The fabrication of Au/Pd plasmonic alloys on UiO-66-NH <sub/>2</sub> : an efficient visible light-induced photocatalyst towards the Suzuki Miyaura coupling reaction under ambient conditions
摘要： Visible light harvesting by heterogeneous photocatalysts and their applications in organic transformation reactions for the synthesis of target molecules are quite demanding science in the current scenario. In this regard, herein, a novel metal (Au/Pd)-functionalized metal organic framework (UiO-66-NH2) was synthesized to carry out the Suzuki–Miyaura coupling (SMC) reaction under visible light irradiation at ambient conditions. In order to justify the claim regarding the formation of alloys, crystallinity, morphology, particle size, proper separation of excitons, elemental content and their environment, various sensitive characterization techniques such as XRD, XPS, HRTEM, BET surface area and UV-vis analysis were employed. A mechanistic approach by means of experimental investigations revealed that the strong LSPR effect of Au facilitated the transfer of electrons to the Pd surface to make the surface negatively charged and suitable for the activation of aryl halides. The formed electropositive Au nanoparticles were converted to Au0 by accepting the photo-induced electrons from pristine UiO-66-NH2 and made available only holes at VB for the activation of phenylboronic acid. Among all the synthesized photocatalysts (1 : 2), Au/Pd@UiO-66-NH2 showed the highest activity (>99%) with TOF = 426 h?1 in an EtOH/H2O medium towards the SMC reaction, and the highest activity of this catalyst was supported by the electron gas model, LSPR effect (UV-vis) and active species separation (PL) analysis. The bimetallic noble nanoparticle-anchored UiO-66-NH2 not only expands the synthesis scope of C–C coupling by the SMC reaction under ambient conditions but will also inspire the further exploration of the activation of various reactants towards a wide range of organic transformation reactions.
关键词： visible light harvesting,Suzuki–Miyaura coupling,heterogeneous photocatalysts,LSPR effect,Au/Pd-functionalized metal organic framework
更新于2025-09-12 10:27:22