| 1. |
- Liu, Yong-feng, et al.
(författare)
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Highly Soluble CsPbBr3 Perovskite Quantum Dots for Solution-Processed Light-Emission Devices
- 2021
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; , s. 1162-1174
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Tidskriftsartikel (refereegranskat)abstract
- We report on the synthesis of CsPbBr3 perovskite quantum dots (PeQDs) with a high solubility of 75 g/L in toluene and a good film-forming property, as enabled by a dense layer of didodecyldimethylammonium bromide and octanoic acid surface ligands. The crystalline and monodisperse PeQDs feature a cubic-like shape, with an edge length of 10.1 nm, and a high photoluminescence quantum yield of greater than 90% in toluene solution and 36% as a thin film. We find that the PeQDs are n-type doped following the synthesis but also that they can be p-type and additionally n-type doped by in situ electrochemistry. These combined properties render the PeQDs interesting for the emitter in solution-processed light-emitting electrochemical cells (LECs), and we report a PeQD-LEC with air-stabile electrodes that emits with a narrow emission spectrum (λpeak = 514 nm, full width at half-maximum = 24 nm) and a luminance of 250 cd/m2 at 4 V and a luminance of 1090 cd/m2 at 6.8 V. To reach this performance, it was critical to include a thin solution-processed layer comprising p-type poly(vinyl carbazole) and a tetrahexylammonium tetrafluoroborate ionic liquid between the PeQD emission layer and the anode in order to compensate for the as-synthesized n-type doping of the PeQDs.
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| 2. |
- Wang, Heyong, et al.
(författare)
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Perovskite-molecule composite thin films for efficient and stable light-emitting diodes
- 2020
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Although perovskite light-emitting diodes (PeLEDs) have recently experienced significant progress, there are only scattered reports of PeLEDs with both high efficiency and long operational stability, calling for additional strategies to address this challenge. Here, we develop perovskite-molecule composite thin films for efficient and stable PeLEDs. The perovskite-molecule composite thin films consist of in-situ formed high-quality perovskite nanocrystals embedded in the electron-transport molecular matrix, which controls nucleation process of perovskites, leading to PeLEDs with a peak external quantum efficiency of 17.3% and half-lifetime of approximately 100 h. In addition, we find that the device degradation mechanism at high driving voltages is different from that at low driving voltages. This work provides an effective strategy and deep understanding for achieving efficient and stable PeLEDs from both material and device perspectives.
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| 3. |
- Wu, Guoqing, et al.
(författare)
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Copper hexacyanoferrate/carbon sheet combination with high selectivity and capacity for copper removal by pseudocapacitance
- 2024
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Ingår i: Journal of Colloid and Interface Science. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0021-9797 .- 1095-7103. ; 659, s. 993-1002
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Tidskriftsartikel (refereegranskat)abstract
- The efficient capture of copper ions (Cu2+) in wastewater has dual significance in pollution control and resource recovery. Prussian blue analog (PBA)-based pseudocapacitive materials with open frameworks and abundant metal sites have attracted considerable attention as capacitive deionization (CDI) electrodes for copper removal. In this study, the efficiency of copper hexacyanoferrate (CuHCF) as CDI electrode for Cu2+ treating was evaluated for the first time upon the successful synthesis of copper hexacyanoferrate/carbon sheet combination (CuHCF/C) by introducing carbon sheet as conductive substrate. CuHCF/C exhibited significant pseudocapacitance and high specific capacitance (52.92 F g-1) through the intercalation, deintercalation, and coupling of Cu+/Cu2+ and Fe2+/Fe3+ redox pairs. At 0.8 an applied voltage and CuSO4 feed liquid concentration of 100 mg L-1, the salt adsorption capacity was 134.47 mg g-1 higher than those of most reported electrodes. Moreover, CuHCF/C demonstrated excellent Cu2+ selectivity in multi -ion coexisting solutions and in actual wastewater experiments. Density functional theory (DFT) calculations were employed to elucidate the mechanism. This study not only reveals the essence of Cu2+ deionization by PBAs pseudocapacitance with promising potential applications but also provides a new strategy for selecting efficient CDI electrodes for Cu2+ removal.
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| 4. |
- Chen, Mengyun, et al.
(författare)
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Kinetically Controlled Synthesis of Quasi-Square CsPbI3 Nanoplatelets with Excellent Stability
- 2023
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Ingår i: Small. - : WILEY-V C H VERLAG GMBH. - 1613-6810 .- 1613-6829.
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Tidskriftsartikel (refereegranskat)abstract
- Nanoplatelets (NPLs) share excellent luminescent properties with their symmetric quantum dots counterparts and entail special characters benefiting from the shape, like the thickness-dependent bandgap and anisotropic luminescence. However, perovskite NPLs, especially those based on iodide, suffer from poor spectral and phase stability. Here, stable CsPbI3 NPLs obtained by accelerating the crystallization process in ambient-condition synthesis are reported. By this kinetic control, the rectangular NPLs into quasi-square NPLs are tuned, where enlarged width endows the NPLs with a lower surface-area-to-volume ratio (S/V ratio), leading to lower surficial energy and thus improved endurance against NPL fusion (cause for spectral shift or phase transformation). The accelerated crystallization, denoting the fast nucleation and short period of growth in this report, is enabled by preparing a precursor with complete transformation of PbI2 into intermediates (PbI3-), through an additional iodide supplier (e.g., zinc iodide). The excellent color stability of the materials remains in the light-emitting diodes under various bias stresses.
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| 5. |
- Chen, Zhan, et al.
(författare)
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Photoluminescence Enhancement for Efficient Mixed-Halide Blue Perovskite Light-Emitting Diodes
- 2023
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Ingår i: Advanced Optical Materials. - : WILEY-V C H VERLAG GMBH. - 2162-7568 .- 2195-1071. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- The development of highly efficient blue perovskite light-emitting diodes (PeLEDs) remains a big challenge, requiring more fundamental investigations. In this work, significant photoluminescence enhancement in mixed halide blue perovskite films is demonstrated by using a molecule, benzylphosphonic acid, which eventually doubles the external quantum efficiency to 6.3% in sky-blue PeLEDs. The photoluminescence enhancement is achieved by forming an oxide-bonded perovskite surface at grain boundaries and suppressing electron-phonon interaction, which enhances the radiative recombination rate and reduces the nonradiative recombination rate, respectively. Moreover, severe thermal quenching is observed in the blue perovskite films, which can be explained by a two-step mechanism involving exciton dissociation and electron-phonon interaction. The results suggest that enhancing the radiative recombination rate and reducing the electron-phonon interaction-induced nonradiative recombination rate are crucial for achieving blue perovskite films with strong emission at or above room temperature.
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| 6. |
- Li, Danqin, et al.
(författare)
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Enhanced and Balanced Charge Transport Boosting Ternary Solar Cells Over 17% Efficiency
- 2020
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 32:34
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Tidskriftsartikel (refereegranskat)abstract
- Ternary architecture is one of the most effective strategies to boost the power conversion efficiency (PCE) of organic solar cells (OSCs). Here, an OSC with a ternary architecture featuring a highly crystalline molecular donor DRTB-T-C4 as a third component to the host binary system consisting of a polymer donor PM6 and a nonfullerene acceptor Y6 is reported. The third component is used to achieve enhanced and balanced charge transport, contributing to an improved fill factor (FF) of 0.813 and yielding an impressive PCE of 17.13%. The heterojunctions are designed using so-called pinning energies to promote exciton separation and reduce recombination loss. In addition, the preferential location of DRTB-T-C4 at the interface between PM6 and Y6 plays an important role in optimizing the morphology of the active layer.
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| 7. |
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| 8. |
- Li, Qifan, et al.
(författare)
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A Highly Conductive n-Type Conjugated Polymer Synthesized in Water
- 2024
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Ingår i: Journal of the American Chemical Society. - : AMER CHEMICAL SOC. - 0002-7863 .- 1520-5126.
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Tidskriftsartikel (refereegranskat)abstract
- Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a benchmark hole-transporting (p-type) polymer that finds applications in diverse electronic devices. Most of its success is due to its facile synthesis in water, exceptional processability from aqueous solutions, and outstanding electrical performance in ambient. Applications in fields like (opto-)electronics, bioelectronics, and energy harvesting/storage devices often necessitate the complementary use of both p-type and n-type (electron-transporting) materials. However, the availability of n-type materials amenable to water-based polymerization and processing remains limited. Herein, we present a novel synthesis method enabling direct polymerization in water, yielding a highly conductive, water-processable n-type conjugated polymer, namely, poly[(2,2 '-(2,5-dihydroxy-1,4-phenylene)diacetic acid)-stat-3,7-dihydrobenzo[1,2-b:4,5-b ']difuran-2,6-dione] (PDADF), with remarkable electrical conductivity as high as 66 S cm(-1), ranking among the highest for n-type polymers processed using green solvents. The new n-type polymer PDADF also exhibits outstanding stability, maintaining 90% of its initial conductivity after 146 days of storage in air. Our synthetic approach, along with the novel polymer it yields, promises significant advancements for the sustainable development of organic electronic materials and devices.
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| 9. |
- Liu, Tiefeng, et al.
(författare)
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Ground-state electron transfer in all-polymer donor:acceptor blends enables aqueous processing of water-insoluble conjugated polymers
- 2023
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Ingår i: Nature Communications. - : NATURE PORTFOLIO. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Water-based conductive inks are vital for the sustainable manufacturing and widespread adoption of organic electronic devices. Traditional methods to produce waterborne conductive polymers involve modifying their backbone with hydrophilic side chains or using surfactants to form and stabilize aqueous nanoparticle dispersions. However, these chemical approaches are not always feasible and can lead to poor material/device performance. Here, we demonstrate that ground-state electron transfer (GSET) between donor and acceptor polymers allows the processing of water-insoluble polymers from water. This approach enables macromolecular charge-transfer salts with 10,000x higher electrical conductivities than pristine polymers, low work function, and excellent thermal/solvent stability. These waterborne conductive films have technological implications for realizing high-performance organic solar cells, with efficiency and stability superior to conventional metal oxide electron transport layers, and organic electrochemical neurons with biorealistic firing frequency. Our findings demonstrate that GSET offers a promising avenue to develop water-based conductive inks for various applications in organic electronics. Chemical approaches to improve aqueous dispersions of conjugated polymers are limited by the feasibility of modifying the backbone or lead to poor performance. Here, Liu et al. show that ground-state electron transfer in donor:acceptor blends aids aqueous dispersion, for high conductivity and solubility.
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| 10. |
- Liu, Tong, et al.
(författare)
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Semitransparent polymer solar cell/triboelectric nanogenerator hybrid systems: Synergistic solar and raindrop energy conversion for window-integrated applications
- 2022
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Ingår i: Nano Energy. - : ELSEVIER. - 2211-2855 .- 2211-3282. ; 103
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Tidskriftsartikel (refereegranskat)abstract
- Development of photovoltaic (PV)-derived hybrid power systems can overcome the weather-dependent elec-tricity production and increase the amount of dispatchable renewable energy generation. Herein, monolithic hybrid devices are developed via rational integration of high-performance semitransparent polymer solar cells (ST-PSCs) and liquid-solid triboelectric nanogenerators (TENGs). High-performance PSCs with efficiencies of 17.4% for rigid and 15.7% for flexible devices are achieved. Further electrode modifications and integration of transparent TENGs synergistically balance the above-bandgap photon harvesting and transparency in a broad wavelength range (380 -1000 nm), yet significantly reduce the transmittance in the near-infrared wavelength range (1000 -2500 nm) of hybrid devices. The hybrid devices simultaneously provide high visible light transparency, good color fidelity, efficient heat resistance and possibility to integrate on rigid and flexible substrates. The hybrid devices attain a high solar conversion efficiency of 10.1% under 1 sun, indicating efficient light-to-electricity conversion (a maximum electrical power output: 101 W m-2) on sunny days. The hybrid devices can also generate a maximum electrical power output of 2.62 W m- 2 through waterdrop energy con-version, implying complementary green electricity production on rainy days. The controlled ambient tempera-ture and specific transmittance windows provided by the hybrid devices sustain plant growth and highlight their great potential in agricultural applications. Gratifyingly, this work demonstrates the first example of ST-PSC/ TENG hybrid systems for scaling up renewable power generation in different weather conditions, considering architectural and agricultural applications.
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