| 1. |
- Chen, Desui, et al.
(författare)
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Shelf-Stable Quantum-Dot Light-Emitting Diodes with High Operational Performance
- 2020
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Ingår i: Advanced Materials. - : Wiley-VCH Verlagsgesellschaft. - 0935-9648 .- 1521-4095. ; 32
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Tidskriftsartikel (refereegranskat)abstract
- Quantum-dot light-emitting diodes (QLEDs) promise a new generation of high-performance, large-area, and cost-effective electroluminescent devices for both display and solid-state lighting technologies. However, a positive ageing process is generally required to improve device performance for state-of-the-art QLEDs. Here, it is revealed that the in situ reactions induced by organic acids in the commonly used encapsulation acrylic resin lead to positive ageing and, most importantly, the progression of in situ reactions inevitably results in negative ageing, i.e., deterioration of device performance after long-term shelf storage. In-depth mechanism studies focusing on the correlations between the in situ chemical reactions and the shelf-ageing behaviors of QLEDs inspire the design of an electron-transporting bilayer, which delivers both improved electrical conductivity and suppressed interfacial exciton quenching. This material innovation enables red QLEDs exhibiting neglectable changes of external quantum efficiency (>20.0%) and ultralong operational lifetime (T-95: 5500 h at 1000 nits) after storage for 180 days. This work provides design principles for oxide electron-transporting layers to realize shelf-stable and high-operational-performance QLEDs, representing a new starting point for both fundamental studies and practical applications.
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| 2. |
- Li, Luoyang, et al.
(författare)
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Qingjianglepas from the Qingjiang biota, an evolutionary dead-end of Cambrian helcionelloid mollusks?
- 2021
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Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182 .- 1872-616X. ; 575, s. 110480-110480
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Tidskriftsartikel (refereegranskat)abstract
- A minute limpet-shaped shell, Qingjianglepas elegans n. gen. n. sp., is reported from the 518 million-year-old Qingjiang biota in Hubei, China. The new shell exhibits a typical limpet morphology with a shell sculpture of strongly developed radial ribs, an anterior shell fold, and distinctive shell shape shift. Feature combinations such as in Qingjianglepas are unique among Cambrian mollusk assemblages, but strikingly resemble that of some modern fissurellids (keyhole and slit limpets; Vetigastropoda). The biological affinity of Qingjianglepas is discussed, but temporarily remains uncertain. Regardless, the heavily sculptured and limpet-shaped Qingjianglepas represents a previously unrecognized shell form, and hence significantly extends the morphological diversity of Cambrian mollusks. The abrupt ontogenetic change in shell morphology suggests that Qingjianglepas might change microhabitat throughout the growth of the animal. This study reveals that the phenomenon of limpetization occurred within early Cambrian total-group conchiferans. Furthermore, Qingjianglepas might represent an evolutionary dead-end in course of helcionelloid mollusk evolution, which marks the end of the Cambrian explosion of animals at the beginning of Cambrian Series 2.
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| 3. |
- Liang, Xiaoyong, et al.
(författare)
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Colloidal metal oxide nanocrystals as charge transporting layers for solution-processed light-emitting diodes and solar cells
- 2017
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Ingår i: Chemical Society Reviews. - : ROYAL SOC CHEMISTRY. - 0306-0012 .- 1460-4744. ; 46:6, s. 1730-1759
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Forskningsöversikt (refereegranskat)abstract
- Colloidal metal oxide nanocrystals offer a unique combination of excellent low-temperature solution processability, rich and tuneable optoelectronic properties and intrinsic stability, which makes them an ideal class of materials as charge transporting layers in solution-processed light-emitting diodes and solar cells. Developing new material chemistry and custom-tailoring processing and properties of charge transporting layers based on oxide nanocrystals hold the key to boosting the efficiency and lifetime of all-solution-processed light-emitting diodes and solar cells, and thereby realizing an unprecedented generation of high-performance, low-cost, large-area and flexible optoelectronic devices. This review aims to bridge two research fields, chemistry of colloidal oxide nanocrystals and interfacial engineering of optoelectronic devices, focusing on the relationship between chemistry of colloidal oxide nanocrystals, processing and properties of charge transporting layers and device performance. Synthetic chemistry of colloidal oxide nanocrystals, ligand chemistry that may be applied to colloidal oxide nanocrystals and chemistry associated with post-deposition treatments are discussed to highlight the ability of optimizing processing and optoelectronic properties of charge transporting layers. Selected examples of solution-processed solar cells and light-emitting diodes with oxide-nanocrystal charge transporting layers are examined. The emphasis is placed on the correlation between the properties of oxide-nanocrystal charge transporting layers and device performance. Finally, three major challenges that need to be addressed in the future are outlined. We anticipate that this review will spur new material design and simulate new chemistry for colloidal oxide nanocrystals, leading to charge transporting layers and solution-processed optoelectronic devices beyond the state-of-the-art.
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| 4. |
- Liang, Xiaoyong, et al.
(författare)
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Synthesis of Unstable Colloidal Inorganic Nanocrystals through the Introduction of a Protecting Ligand
- 2014
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Ingår i: Nano letters (Print). - : American Chemical Society. - 1530-6984 .- 1530-6992. ; 14:6, s. 3117-3123
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a facile and general strategy based on ligand protection for the synthesis of unstable colloidal nanocrystals by using the synthesis of pure p-type NiO nanocrystals as an example. We find that the introduction of lithium stearate, which is stable in the reaction system and capable of binding to the surface of NiO oxide nanocrystals, can effectively suppress the reactivity of NiO nanocrystals and thus prevent their in situ reduction into Ni. The resulting p-type NiO nanocrystals, a highly demanded hole-transporting and electron-blocking material, are applied to the fabrication of organic solar cells and polymer light-emitting diodes, demonstrating their great potential as an interfacial layer for low-cost and large-area, solution-processed optoelectronic devices.
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