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Carbon quantum dots modified anatase/rutile TiO2 photoanode with dramatically enhanced photoelectrochemical performance
摘要： Titanium dioxide (TiO2) is a promising photoanode material for photoelectrochemical (PEC) water splitting, but the severe bulk recombination of photongenerated carriers, the sluggish oxygen evolution reaction (OER) kinetics and the poor visible light response are the main bottleneck problems. Here, the carbon quantum dots (CQDs) modified anatase/rutile TiO2 photoanode (CQDs/A/R-TiO2) was designed by growth of anatase TiO2 nanothorns on the rutile TiO2 nanorods and further surface modification of CQDs. The results revealed that A/R-TiO2 heterojunction significantly suppressed the bulk recombination of photogenerated carriers. With further incorporation of CQDs into A/R-TiO2, dramatical improvement of OER kinetics and light harvesting were obtained. The bulk charge separation efficiency (ηbulk) and the surface charge injection efficiency (ηsurface) of CQDs/A/R-TiO2 are 1.69 and 5.74 times higher than that of the pristine TiO2 at 0.6 V vs. RHE, respectively. The photocurrent of CQDs/A/R-TiO2 is increased by 11.72 times and the onset potential of CQDs/A/R-TiO2 is negatively shifted by 240 mV.
关键词： Anatase/rutile TiO2 heterojunction,Carbon quantum dots,Bulk and surface charge transfer kinetics,PEC,Light harvesting
更新于2025-09-23 15:19:57
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Recent Progress in Indoor Organic Photovoltaics
摘要： Among various potential applications of organic photovoltaics (OPVs), indoor power generation has great potential because of several advantages over outdoor light harvesting under 1 sun condition. Commonly used indoor light sources have narrower emission spectra with lower intensity (by 3 orders of magnitude) as compared to the solar spectrum. Highly tunable optical absorption, large absorption coefficient, and small leakage currents under dim lighting conditions make OPVs promising candidates for indoor applications. For optimizing indoor photovoltaic materials and devices, several key issues (different from those under 1 sun condition), such as developing new indoor photovoltaic materials and devices with suitable absorption spectrum, large open-circuit voltage with low energy loss, minimized trap-mediated charge recombination and leakage currents, and device stability under indoor conditions, should be considered carefully. In this review, recent progresses in optimization of indoor photovoltaic materials and devices, and the key strategies to optimize the indoor photovoltaic characteristics will be summarized and discussed.
关键词： device optimization,light harvesting,organic photovoltaics,indoor power generation,photovoltaic materials
更新于2025-09-23 15:19:57
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Upconverting carbon quantum dots: An eco-friendly material for light energy harvesting and bio-imaging
摘要： Eco-friendly carbon quantum dots (CQDs) are finding many applications in the field of chemical sensing, photocatalytic applications, photovoltaic applications, bio-imaging, etc. Herein, CQDs are grown via a cost-effective manner, where the lemon and onion extracts are used as the reaction precursors. Formed CQDs are characterized using electronic spectroscopic and microscopic techniques. The emission yield of the present CQDs is found to be 11.2%. In contrast to general fluorophores/ semiconductors, this material showed an upconverting photoluminescence. Upon exciting with a lower energy continuous wave light of 695 nm, we observed an upconverted emission centered at 438 nm. For upconversion, as the excitation wavelength is at the lower energy, the photodecomposition of the material will be minimum. This will increase the efficiency and the lifetime of the light harvesting devices as the photodecomposition is minimum at lower wavelengths. Also, upconverting CQDs can be a potential candidate for the bio-imaging applications as the light induced decomposition of the biological samples will be minimum.
关键词： Eco-friendly material,Carbon quantum dots,Light harvesting applications,Upconversion
更新于2025-09-23 15:19:57
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Synergy of light harvesting and energy transfer as well as short-range charge shift reactions in multicomponent conjugates
摘要： We report herein on the design, the synthesis, and the characterization of a panchromatic, charge stabilizing electron donor–acceptor conjugate: (BBPA)3–ZnPor–ZnPc–SubPc 1. Each component, that is, bis(biphenyl)phenylamine (BBPA), Zn(II) porphyrin (ZnPor), Zn(II) phthalocyanine ZnPc, and subphthalocyanine (SubPc), has been carefully chosen and modified to enable a cascade of energy and charge transfer processes. On one hand, ZnPor, has been functionalized with three electron-donating BBPA as primary and secondary electron donors and to stabilize the final charge-separated state, and, on the other hand, a perfluorinated SubPc has been selected as ultimate electron acceptor. In addition, the ZnPc unit contains several trifluoromethylphenyl moieties to match its energy levels to those of the other components. In fact, irradiation of the heteroarray 1 triggers a cascade of light harvesting across the entire visible range, unidirectional energy transfer, exergonic charge separating, and short-range charge shifting to afford a (BBPA)3(cid:129)+–ZnPor–ZnPc–SubPc(cid:129)? charge-separated state. The lifetime of the latter reaches well into the range of tens of nanoseconds with a 14% quantum yield.
关键词： charge stabilizing,light harvesting,panchromatic,charge transfer,energy transfer,porphyrinoids,electron donor–acceptor conjugate
更新于2025-09-19 17:15:36
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Organic functional materials: recent advances in all-inorganic perovskite solar cells
摘要： Although the power conversion e?ciency (PCE) of organic–inorganic hybrid perovskite solar cells (PSCs) is comparable to those of commercial solar cells, a challenging problem of instability hampers their further commercialization. In recent years, in comparison with organic–inorganic hybrid PSCs, cesium-based all-inorganic perovskites show better light, moisture and especially thermal stability, and therefore they have exhibited great potential and received widespread attention. However, an unavoidable issue is that the PCE of all-inorganic PSCs still lags behind that of hybrid perovskite devices. To solve this problem, some organic or inorganic interlayer materials are introduced into all-inorganic PSCs as additive, passivation agent and charge transport materials to improve device performance. Compared to inorganic materials, organic materials present some advantages, such as energy level controllability, molecular structure diversity, and surface wettability modi?cations. Thus, the PCE of all-inorganic PSCs has been signi?cantly improved through the use of organic materials. In this review, we summarized the recent strategies for improving the performance of all-inorganic PSCs through organic interlayer materials, including crystallization control, defect passivation, interface engineering, and expanding the light harvesting capability. Finally, a perspective on challenges and opportunities is proposed in the ?eld.
关键词： organic interlayer materials,crystallization control,defect passivation,all-inorganic perovskite solar cells,light harvesting,interface engineering
更新于2025-09-19 17:13:59
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Extending the Photovoltaic Response of Perovskite Solar Cells into the Near‐Infrared with a Narrow‐Bandgap Organic Semiconductor
摘要： Typical lead-based perovskites solar cells show an onset of photogeneration around 800 nm, leaving plenty of spectral loss in the near-infrared (NIR). Extending light absorption beyond 800 nm into the NIR should increase photocurrent generation and further improve photovoltaic efficiency of perovskite solar cells (PSCs). Here, a simple and facile approach is reported to incorporate a NIR-chromophore that is also a Lewis-base into perovskite absorbers to broaden their photoresponse and increase their photovoltaic efficiency. Compared with pristine PSCs without such an organic chromophore, these solar cells generate photocurrent in the NIR beyond the band edge of the perovskite active layer alone. Given the Lewis-basic nature of the organic semiconductor, its addition to the photoactive layer also effectively passivates perovskite defects. These films thus exhibit significantly reduced trap densities, enhanced hole and electron mobilities, and suppressed illumination-induced ion migration. As a consequence, perovskite solar cells with organic chromophore exhibit an enhanced efficiency of 21.6%, and substantively improved operational stability under continuous one-sun illumination. The results demonstrate the potential generalizability of directly incorporating a multifunctional organic semiconductor that both extends light absorption and passivates surface traps in perovskite active layers to yield highly efficient and stable NIR-harvesting PSCs.
关键词： narrow-bandgap organic semiconductors,perovskite solar cells,NIR light harvesting,passivation
更新于2025-09-19 17:13:59
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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
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Realizing Stable Artificial Photon Energy Harvesting Based on Perovskite Solar Cells for Diverse Applications
摘要： As the fastest developing photovoltaic device, perovskite solar cells have achieved an extraordinary power conversion efficiency (PCE) of 25.3% under AM 1.5 illumination. However, few studies have been devoted to perovskite solar cells harvesting artificial light, owing to the great challenge in the simultaneous manipulation of bandgap-adjustable perovskite materials, corresponding matched energy band structure of carrier transport materials, and interfacial defects. Herein, through systematic morphology, composition, and energy band engineering, high-quality Cs0.05MA0.95PbBrxI3?x perovskite as the light absorber and NbyTi1?yO2 (Nb:TiO2) as the electron transport material with an ideal energy band alignment are obtained simultaneously. The theoretical-limit-approaching record PCEs of 36.3% (average: 34.0 ± 1.2%) under light-emitting diode (LED, warm white) and 33.2% under fluorescent lamp (cold white) are achieved simultaneously, as well as a PCE of 19.5% (average: 18.9 ± 0.3%) under solar illumination. An integrated energy conversion and storage system based on an artificial light response solar cell and sodium-ion battery is established for diverse practical applications, including a portable calculator, quartz clock, and even environmental monitoring equipment. Over a week of stable operation shows its great practical potential and provides a new avenue to promote the commercialization of perovskite photovoltaic devices via integration with ingenious electronic devices.
关键词： energy band engineering,weak light harvesting,perovskite solar cells,indoor application
更新于2025-09-19 17:13:59
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PMMA Thin Film with Embedded Carbon Quantum Dots for Post-Fabrication Improvement of Light Harvesting in Perovskite Solar Cells
摘要： Perovskite solar cells (PSCs) with a standard sandwich structure suffer from optical transmission losses due to the substrate and its active layers. Developing strategies for compensating for the losses in light harvesting is of significant importance to achieving a further enhancement in device efficiencies. In this work, the down-conversion effect of carbon quantum dots (CQDs) was employed to convert the UV fraction of the incident light into visible light. For this, thin films of poly(methyl methacrylate) with embedded carbon quantum dots (CQD@PMMA) were deposited on the illumination side of PSCs. Analysis of the device performances before and after application of CQD@PMMA photoactive functional film on PSCs revealed that the devices with the coating showed an improved photocurrent and fill factor, resulting in higher device efficiency.
关键词： PMMA,light harvesting,carbon quantum dots,Perovskite solar cell,down-conversion
更新于2025-09-19 17:13:59
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CsPbBr <sub/>3</sub> Quantum Dots as Artificial Antennas to Enhance the Light-Harvesting Efficiency and Photoresponse of Zinc Porphyrin
摘要： Broadening the spectral range and enhancing the efficiency of light-harvesting materials are important to the design of novel optoelectronic devices. In this work, CsPbBr3 quantum dots (QDs) are introduced as artificial antennas to enhance both the light-harvesting efficiency and photoresponse of zinc porphyrin (ZnP). The Fluorescence Resonance Energy Transfer (FRET) process both in solution and films from the donor CsPbBr3 QD to the acceptor ZnP have been systematically investigated, and an energy transfer efficiency over 70% in solution and a high optical sensitivity have been realized with the optimal of QD/ZnP ratio on films. A photocurrent density of up to 1.00×10-4 A·cm-2 can be achieved for the QD/ZnP film, and the corresponding on/off photocurrent value can be increased by two orders of magnitude compared with that of ZnP. Furthermore, the as-prepared light-harvesting film also demonstrates a high optical sensitivity at the optimal QD/ZnP ratio. Our research provides an effective way for designing and improving the QD/ZnP “antenna” for solar-energy harvesting devices.
关键词： Zinc Porphyrin,CsPbBr3 Quantum Dots,FRET,Photoresponse,Light-Harvesting Efficiency
更新于2025-09-19 17:13:59