| 1. |
- Li, Jian, et al.
(author)
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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO4+δ
- 2020
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Journal article (peer-reviewed)abstract
- CeNbO4+δ, a family of oxygen hyperstoichiometry materials with varying oxygen content (CeNbO4, CeNbO4.08, CeNbO4.25, CeNbO4.33) that shows mixed electronic and oxide ionic conduction, has been known for four decades. However, the oxide ionic transport mechanism has remained unclear due to the unknown atomic structures of CeNbO4.08 and CeNbO4.33. Here, we report the complex (3 + 1)D incommensurately modulated structure of CeNbO4.08, and the supercell structure of CeNbO4.33 from single nanocrystals by using a three-dimensional electron diffraction technique. Two oxide ion migration events are identified in CeNbO4.08 and CeNbO4.25 by molecular dynamics simulations, which was a synergic-cooperation knock-on mechanism involving continuous breaking and reformation of Nb2O9 units. However, the excess oxygen in CeNbO4.33 hardly migrates because of the high concentration and the ordered distribution of the excess oxide ions. The relationship between the structure and oxide ion migration for the whole series of CeNbO4+δ compounds elucidated here provides a direction for the performance optimization of these compounds.
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| 2. |
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| 3. |
- Xiong, Shaobing, et al.
(author)
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Direct Observation on p- to n-Type Transformation of Perovskite Surface Region during Defect Passivation Driving High Photovoltaic Efficiency
- 2021
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In: Joule. - : CELL PRESS. - 2542-4351. ; 5:2, s. 467-480
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Journal article (peer-reviewed)abstract
- Perovskite solar cells (PSCs) suffer from significant nonradiative recombination, limiting their power conversion efficiencies. Here, for the first time, we directly observe a complete transformation of perovskite MAPbI(3) surface region energetics from p- to n-type during defect passivation caused by natural additive capsaicin, attributed to the spontaneous formation of a p-n homojunction in perovskite active layer. We demonstrate that the p-n homojunction locates at similar to 100 nm below perovskite surface. The energetics transformation and defect passivation promote charge transport in bulk perovskite layer and at perovskite/PCBM interface, suppressing both defect-assisted recombination and interface carrier recombination. As a result, an efficiency of 21.88% and a fill factor of 83.81% with excellent device stability are achieved, both values are the highest records for polycrystalline MAPbI(3) based p-i-n PSCs reported to date. The proposed new concept of synergetic defect passivation and energetic modification via additive provides a huge potential for further improvement of PSC performance.
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| 4. |
- Zeng, Jianhua, et al.
(author)
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Intrinsically stretchable tribotronic mechanoplastic artificial synapse
- 2024
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In: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 492
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Journal article (peer-reviewed)abstract
- Stretchable synaptic devices with adaptability to elastic deformation, sensing environmental stimuli, and unique information processing functions are of great significance for the development of the next generation of artificial nervous systems. Here, an intrinsically stretchable tribotronic mechanoplastic artificial synapse (STMAS) is proposed, which is integrated by a triboelectric nanogenerator and an electrolyte-gated transistor with ion-gel as dielectric layer. The STMAS can be modulated by the triboelectric potential induced by mechanical stimulation without the need to apply an external gate voltage, achieving an active mechanical tuning of synaptic plasticity such as excitatory postsynaptic current, paired-pulse facilitation, short-term plasticity, and long-term plasticity. The STMAS exhibits stable synaptic plasticity under 0–50% stretcher strain in parallel and vertical to channel directions, respectively. Furthermore, the International Morse code triggered by mechanical signals has been successfully mimicked. This work has achieved an intrinsically stretchable tribotronic artificial synapse with mechanically tuned synaptic behavior, which will help promote the development of artificial nervous systems and expand the applications of artificial synapses in intelligent robotics, artificial limbs and human–machine interaction.
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