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Direct Hot-Injection Synthesis of Lead Halide Perovskite Nanocubes in Acrylic Monomers for Ultrastable and Bright Nanocrystal–Polymer Composite Films
摘要: In recent years, lead halide perovskite nanocrystals (NCs) have attracted significant attention in both fundamental research and commercial applications due to their excellent optical and optoelectrical properties. However, the protective ligands on the surface of the perovskites NCs could be easily removed after the tedious process of centrifugation, separation, and dispersion, which greatly hampers their stability against light, heat, moisture, and oxygen and limits their practical applications. Here we report a new post-processing-free strategy (i.e., without centrifugation, separation, and dispersion process) of using an UV-polymerizable acrylic monomer of lauryl methacrylate (LMA) as the solvent to synthesize CsPbBr3 NCs, and then adding polyester polyurethane acrylates oligomer, monomer (IBOA) and initiator for directly UV polymerization to fabricate NC-polymer composite films. These films exhibited an improved photoluminescence quantum yield (85-90%) than classic NC-film (40-50%), which were processed using octadecene (ODE) as the solvent for NC synthesis and post-processed for UV polymerization. Significantly, the as-fabricated films by post-processing-free strategy exhibited excellent photostability against strong Xe lamp illumination; while the other films using classic methods were quickly photo-degraded. Meanwhile, these NC-polymer composite films showed good stability against moisture and heating when aging in water at 50oC for over 200 hours. These films, along with K2SiF6:Mn4+ (KSF) phosphor emitters, were used as downconverters for blue LEDs in liquid crystal displays with a wide color gamut of 115% in the International Commission on Illumination (CIE) 1931 color space. This work provides a facile and effective strategy for the preparation of ultrastable and bright color-conversion NC films for the development of the next-generation wide color gamut displays.
关键词: display backlight,lead halide perovskite,colloidal nanocrystals,color-conversion optical films,photostability
更新于2025-11-14 17:03:37
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Enhanced Single-Mode Lasers of All-Inorganic Perovskite Nanocube by Localized Surface Plasmonic Effect from Au Nanoparticles
摘要: Miniaturized laser sources recently attracted considerable interests as their potential applications in optical communication, data storage, and imaging. However, high cavity losses induced by size reduction from the gain medium would lead high lasing threshold. In this work, the enhanced optical properties of CsPbBr3 perovskite nanocubes by using localized surface plasmonic effect of Au nanoparticles (NPs) were investigated. The integration of Au NPs in the poly (3, 4-ethylenedioxy-thiophene): poly (styrenesulfonate) PEDOT: PSS layer induces obviously enhancement both in the absorption and photoluminescence (PL) of CsPbBr3 perovskite nanocubes. Importantly,the lasing threshold of CsPbBr3 perovskite nanocubes is significantly reduced by ~ 33%. This study suggests that the lead halide perovskites hybridized with plasmonic nanomaterials would be promising candidates for laser devices and other optoelectronic devices with high efficiency.
关键词: Low threshold,Perovskite nanocubes,LSPR,Au nanoparticles
更新于2025-11-14 15:32:45
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Increasing photoluminescence quantum yield by nanophotonic design of quantum-confined halide perovskite nanowire arrays
摘要: High photoluminescence quantum yield (PLQY) is required to reach optimal performance in solar cells, lasers and light-emitting diodes (LEDs). Typically, PLQY can be increased by improving the material quality to reduce the non-radiative recombination rate. It is in principle equally effective to improve the optical design by nanostructuring a material to increase light out-coupling efficiency and introduce quantum confinement, both of which can increase the radiative recombination rate. However, increased surface recombination typically minimizes nanostructure gains in PLQY. Here a template guided vapor phase growth of CH3NH3PbI3 (MAPbI3) nanowire (NW) arrays with unprecedented control of NW diameter from the bulk (250 nm) to the quantum confined regime (5.7 nm) is demonstrated, while simultaneously providing a low surface recombination velocity of 18 cm s-1. This enables a 56-fold increase in the internal PLQY, from 0.81 % to 45.1 %, and a 2.3-fold increase in light out-coupling efficiency to increase the external PLQY by a factor of 130, from 0.33 % up to 42.6 %, exclusively using nanophotonic design.
关键词: light out-coupling,photoluminescence quantum yield,quantum confinement,perovskite,photodetector
更新于2025-11-14 15:28:36
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Stable Hybrid Perovskite MAPb(I1?Br )3 for Photocatalytic Hydrogen Evolution
摘要: Hybrid organic-inorganic perovskites have been pursuing for solar/visible-driven H2 evolution from hydrohalic acid (HX) splitting, but their inherent structural stability and performance are still challenging. Herein, we report on a stable hybrid perovskite MAPb(I1?xBrx)3 (x = 0 – 0.20) obtained by one-pot crystallization in a mixed halide parent solution and its implementation as a newcomer photocatalyst for H2 evolution in aqueous HX solution. MAPb(I1?xBrx)3 is demonstrated to be a superior visible-light-driven photocatalyst for H2 evolution in aqueous HI/HBr solution with no Pt as a cocatalyst. An optimized MAPb(I1?xBrx)3 (x = 0.10) shows a highest H2 evolution rate of 1471 μmol h?1 g?1 under visible light (λ ≥ 420 nm) illumination, which is ~ 40 times higher than that of pure MAPbI3, and the dual-halide perovskite is rather stable showing no obvious decrease in the photocatalytic activity over 60 runs (252 h). The perovskite inherent structural stability is further evidenced by XRD, UV-vis spectra and EDS elemental mapping of MAPb(I1?xBrx)3 measured after cycled photocatalytic reaction. The solar HI splitting efficiency of MAPb(I1?xBrx)3 (x = 0.10) is determined as 1.42%. The mechanism behind photocatalytic H2 evolution enhancement is elucidated by the experimental and computational methods.
关键词: photocatalyst,MAPb(I1?xBrx)3,hydrogen evolution,perovskite,visible light
更新于2025-11-14 15:28:36
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Dendritic PAMAM polymers for strong perovskite intergranular interaction enhancing power conversion efficiency and stability of perovskite solar cells
摘要: The modification of perovskite intergranular perovskite/perovskite interface plays a critical role for power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). In this work, polyamidoamine (PAMAM) dendrimers are utilized as the dendritic crystallization framework templating the perovskite-crystallizing process. The interactions at the perovskite intergranular interface are considerably strengthened at an ambient environment with dendritic PAMAMs crosslinking the perovskite grains. Consequently, the perovskite morphology is remarkably improved by suppressing the grain/grain-aggregate boundaries for the pinhole removal, which produces a compact, uniform and non-pinhole perovskite film. Finally, the strengthened interfacial interactions dramatically enhance the PCE value of unencapsulated PSCs about 42.6% at an ambient condition. Besides, the unencapsulated PAMAM-modified device can keep 73% of initial PCE value in 400 h while the control device decays to 5% of initial PCE value in 50 h. These results reveal that dendritic polymers might remarkably improve the PCE value and the stability of PSCs. This work provides a new molecular design guideline to effectively regulate the perovskite intergranular interfacial interactions.
关键词: Grain boundary,Interfacial interaction,Intergranular interface,Dendrimer,Perovskite solar cell
更新于2025-11-14 15:27:09
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One-step fabrication of effective mesoporous layer consisted of self-assembled MgO/TiO<sub>2</sub> core/shell nanoparticles for mesostructured perovskite solar cells
摘要: perovskite directly, which can not only passivate surface defects and reduce charge-suppressed J-V hysteresis. Meanwhile, the photovoltaic characteristics and the well-power conversion efficiency (PCE) was increased from 13.13% to 16.30% with well-interface and electrons transfer in PSCs. Based on the mesoporous layer consisting of nanoparticles instead of adding an additional surface modified layer for mesostructured recombination, but also facilitate charge-extraction at the mesoporous layer/perovskite perovskite solar cells (PSCs). An amorphous ultrathin outer nanolayer of MgO was Such self-assembled MgO/TiO2 core/shell nanostructures would retain the mesoporous of PSCs was 1.00 V, 4.2% higher than the uncoated TiO2 based PSCs, and the obtained structure feature, supply more contact interface of MgO/TiO2 and separate the TiO2 and conformally coated onto TiO2 core nanoparticles in a one-step bottom-up approach. proposed an efficient nanoparticulate mesoporous layer consisted of coated TiO2 optimized MgO-coated TiO2 nanoparticles, the corresponding open circuit voltage (VOC) Considering the intrinsic rich defect, poor H2O or UV light stability of TiO2, we resistance is obtained for the cell based on m-TiO2 with MgO coating. In addition, we behaved junction property were further clarified by the ideal model, a much lower series provided an easy regulated uniform coating route to fabricate well-defined core-shell nanoparticles with modified properties.
关键词: Uniform coating,mesoporous layer,Core-shell nanostructure,Perovskite solar cells
更新于2025-11-14 15:27:09
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Solubilization of Carbon Nanotubes with Ethylene-Vinyl Acetate for Solution-Processed Conductive Films and Charge Extraction Layers in Perovskite Solar Cells
摘要: Carbon nanotube (CNT) solubilization via non-covalent wrapping of conjugated semiconducting polymers is a common technique used to produce stable dispersions for depositing CNTs from solution. Here, we report the use of a non-conjugated insulating polymer, ethylene vinyl acetate (EVA), to disperse multi- and single-walled CNTs (MWCNT and SWCNT) in organic solvents. We demonstrate that despite the insulating nature of the EVA, we can produce semitransparent films with conductivities of up to 34 S/cm. We show, using photoluminescence spectroscopy, that the EVA strongly binds to individual CNTs, thus making them soluble, preventing aggregation, and facilitating the deposition of high-quality films. To prove the good electronic properties of this composite, we have fabricated perovskite solar cells using EVA/SWCNTs and EVA/MWCNTs as selective hole contact, obtaining power conversion efficiencies of up to 17.1%, demonstrating that the insulating polymer does not prevent the charge transfer from the active material to the CNTs.
关键词: perovskite solar cells,carbon nanotubes,insulating polymer,conductive films,CNT polymer functionalization
更新于2025-11-14 15:25:21
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Charge extraction via graded doping of hole transport layers gives highly luminescent and stable metal halide perovskite devices
摘要: One source of instability in perovskite solar cells (PSCs) is interfacial defects, particularly those that exist between the perovskite and the hole transport layer (HTL). We demonstrate that thermally evaporated dopant-free tetracene (120 nm) on top of the perovskite layer, capped with a lithium-doped Spiro-OMeTAD layer (200 nm) and top gold electrode, offers an excellent hole-extracting stack with minimal interfacial defect levels. For a perovskite layer interfaced between these graded HTLs and a mesoporous TiO2 electron-extracting layer, its photoluminescence yield reaches 15% compared to 5% for the perovskite layer interfaced between TiO2 and Spiro-OMeTAD alone. For PSCs with graded HTL structure, we demonstrate efficiency of up to 21.6% and an extended power output of over 550 hours of continuous illumination at AM1.5G, retaining more than 90% of the initial performance and thus validating our approach. Our findings represent a breakthrough in the construction of stable PSCs with minimized nonradiative losses.
关键词: perovskite solar cells,stability,charge extraction,photoluminescence,hole transport layers,graded doping
更新于2025-11-14 15:25:21
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All-Thin-Film Tandem Cells Based on Liquid Phase Crystallized Silicon and Perovskites
摘要: Combining the emerging perovskite solar cell technology with existing silicon approaches in a tandem cell design offers the possibility for new low-cost high-performance devices. In this study, the potential of liquid phase crystallized silicon (LPC-Si) solar cells as a bottom cell in an all-thin-film tandem device is investigated. By optimizing the current output of a four terminal tandem using optical simulations and state-of-the-art electrical properties of the top and bottom cells, we show that an efficiency of 23.3% can be reached, where 7.2% are attributed to the LPC-Si bottom cell. Including the potential of future developments of both sub cells, efficiencies of over 28% are estimated. Electrical and optical measurements of the bottom cell are performed by attaching a perovskite and a cutoff filter to the front side of the interdigitated back contacted LPC-Si cells. The measurements using a cutoff filter show a high impact of the filtered incident light spectrum on the open circuit voltage of the LPC-Si cell. A comparison of the simulated and measured absorptance shows that especially the optical properties of the transparent conductive oxides and recombination losses in the LPC-Si cause high current losses. Combining the measured data of the filtered LPC-Si cells and the semitransparent perovskite cells, yields a realistic estimation for the efficiency of a state-of-the-art four-terminal tandem device of 19.3%.
关键词: tandem devices,Liquid phase crystallization (LPC),perovskite solar cells,thin film photovoltaics
更新于2025-11-14 15:25:21
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MAPbI3/agarose photoactive composite for highly stable unencapsulated perovskite solar cells in humid environment
摘要: Perovskite solar cells, bearing the merits of facile preparaion and remarkable efficiency, has great potential for bringing the photovoltaic industry to a new generation. The photovoltaic market demands high-efficiency, high stability and low-cost fabrication of perovksite solar cells, especially stability to the humid environment for operation. Here, MAPbI3/agarose photoactive material for humid stable unencapsulated devices has been proposed. These solar cells have been operated in ambient humid environment without glove box, exhibiting efficiency up to 14.66% and retain 90% of its PCE after 1392 h and 60% of initial PCE after 1972 h in ambient humid environment (RH>70%) without encapsulation. FTIR and XPS measurements reveal two critical factors for the improved stability. The molecular level interactions between agarose and MAPbI3 passivates the grain boundaries of perovskite thus preventing its degradation. Moreover, the formation of Li+-agarose complex at the interface between perovskite layer and hole conductive layer, effectively prevents the water uptake of MAPbI3 layer. Both effects of passivation and minimization of hygroscopicity of LiTFSI by agarose lower the decomposition speed of perovskite, which obviously increases the power efficiency and stability of device.
关键词: humid stability mechanism,perovskite solar cells,MAPbI3/agarose photoactive composite
更新于2025-11-14 15:24:45