Hollow CuSbSy coated by nitrogen-doped carbon as anode electrode for high-performance potassium-ion storage. - In: Batteries, ISSN 2313-0105, Bd. 9 (2023), 5, 238, S. 1-15
As a potential anode material for potassium-ion batteries (PIBs), bimetallic sulfides are favored by researchers for their high specific capacity, low cost, and long cycle life. However, the non-ideal diffusion rate and poor cycle stability pose significant challenges in practical applications. In this work, bimetallic sulfide CuSbSyC with a yolk-shell structure was synthesized by in situ precipitation and carbonization. When CuSbSy is applied in the anode of PIBs, it can provide the desired capacity and reduce the volume expansion of the compound through the synergistic effect between copper and antimony. At the same time, the existence of the nitrogen-doped carbon shell confines the material within the shell while improving its electrical conductivity, inhibiting its volume expansion and aggregation. Therefore, CuSbSy@C exhibits a satisfactory capacity (438.8 mAh g^-1 at 100 mA g^-1 after 60 cycles) and an excellent long cycle life (174.5 mAh g^-1 at 1000 mA g^-1 after 1000 cycles).
https://doi.org/10.3390/batteries9050238
Deep ultraviolet phototransistor based on thiophene-fluorobenzene oligomer with high mobility and performance. - In: Chinese journal of chemistry, ISSN 1614-7065, Bd. 41 (2023), 13, S. 1539-1544
Deep ultraviolet (UV) photodetectors have important applications in the industrial and military fields. However, little research has been reported on organic phototransistors (OPTs) in the deep ultraviolet range. Here, a novel organic semiconductor containing a small torsion angle and low π-conjugation 2,2':5',2”-terthiophene groups, oF-PTTTP, is designed and synthesized, which exhibits high carrier mobility and unique deep ultraviolet response. Accordingly, an OPT based on oF-PTTTP single crystal shows high responsivity to deep-UV light. The photodetectors achieve high photoresponsivity (R) of 857 A/W and detectivity (D*) of 3.2×10^15 Jones under 280 nm light illumination (only 95 nW&hahog;cm^-2). To the best of our knowledge, 280 nm is the deepest detection wavelength reported for organic phototransistors and this work presents a new molecule design concept for organic phototransistors with deep-UV detection.
https://doi.org/10.1002/cjoc.202200795
Hierarchical mesoporous NiO nanosheet arrays as integrated electrode for hybrid sodium-air batteries. - In: Ceramics international, ISSN 1873-3956, Bd. 49 (2023), 13, S. 21355-21362
Attributed to its environmental friendliness, high theoretical energy density, and abundant sodium resource, rechargeable hybrid sodium-air batteries (HSABs) are expected to become a promising pioneer of the new-generation green energy storage device. However, HSABs suffer from the high voltage gap, low energy conversion efficiency, and poor cycle stability due to the low catalytic activity of catalysts caused by the degradation of polymer binders. Herein, hierarchical mesoporous NiO nanosheet arrays grown on carbon papers (CP) (NiO NACP) were synthesized by a facile and efficient hydrothermal route and calcination process, which acts as an integrated electrode for HSABs. Compared with traditional air electrodes that contain a polymer binder and conductive carbon, the integrated NiO NA@CP electrode prevents the aggregation of catalysts, improves the electronic conductivity by good electric contact and ensures its robust mechanical stability. In addition, NiO NA@CP electrode with the abundant porosity and large specific area offers plenty of active sites and shortens ion transfer length and rapid mass transport in ORR/OER process, leading to excellent oxygen catalytic activities. HSABs with NiO NA@CP electrode show a low overpotential of 0.65 V, a state-of-the-art power density (7.53 mW cm^-2), as well as an excellent cyclability of 170 cycles (over 170 h) at a current density of 0.1 mA cm^-2.
https://doi.org/10.1016/j.ceramint.2023.03.264
Integration of cointercalation and adsorption enabling superior rate performance of carbon anodes for symmetric sodium-ion capacitors. - In: ACS applied materials & interfaces, ISSN 1944-8252, Bd. 15 (2023), 20, S. 24459-24469
Carbon materials have been the most common anodes for sodium-ion storage. However, it is well-known that most carbon materials cannot obtain a satisfactory rate performance because of the sluggish kinetics of large-sized sodium-ion intercalation in ordered carbon layers. Here, we propose an integration of co-intercalation and adsorption instead of conventional simplex-intercalation and adsorption to promote the rate capability of sodium-ion storage in carbon materials. The experiment was demonstrated by using a typical carbon material, reduced graphite oxide (RGO400) in an ether-solvent electrolyte. The ordered and disordered carbon layers efficiently store solvated sodium ions and simplex sodium ions, which endows RGO400 with enhanced reversible capacity (403 mA h g^-1 at 50 mA g^-1 after 100 cycles) and superior rate performance (166 mA h g^-1 at 20 A g^-1). Furthermore, a symmetric sodium-ion capacitor was demonstrated by employing RGO400 as both the anode and cathode. It exhibits a high energy density of 48 W h g^-1 at a very high power density of 10,896 W kg^-1. This work updates the sodium-ion storage mechanism and provides a rational strategy to realize high rate capability for carbon electrode materials.
https://doi.org/10.1021/acsami.3c02404
Coupling of photonic and plasmonic modes for double nanowire cavities. - In: Photonics, ISSN 2304-6732, Bd. 10 (2023), 4, 415, S. 1-11
We analyze the coupling between double nanowire cavities for both photonic modes and plasmonic modes. When the spacing between nanowires reduces, a redshift of the resonant frequency of the symmetric mode and a blueshift of the resonant frequency of the antisymmetric mode are observed. Compared to single nanowire cavity modes, the Q factors of antisymmetric supermodes of double nanowires can be improved by 51% for photonic modes and by 24% for plasmonic modes. The mechanisms of Q factor improvement for photonic modes and plasmonic modes are studied based on the field distribution of radiations from the modes. This paper may contribute to research and applications for double nanowire lasers and nanowire laser arrays.
https://doi.org/10.3390/photonics10040415
Data-driven forecasting of nonequilibrium solid-state dynamics. - In: Physical review, ISSN 2469-9969, Bd. 107 (2023), 18, 184306, S. 184306-1-184306-18
We present a data-driven approach to efficiently approximate nonlinear transient dynamics in solid-state systems. Our proposed machine-learning model combines a dimensionality reduction stage with a nonlinear vector autoregression scheme. We report an outstanding time-series forecasting performance combined with an easy-to-deploy model and an inexpensive training routine. Our results are of great relevance as they have the potential to massively accelerate multiphysics simulation software and thereby guide the future development of solid-state-based technologies.
https://doi.org/10.1103/PhysRevB.107.184306
Recent progress and future prospect of novel multi-ion storage devices. - In: Journal of semiconductors, ISSN 2058-6140, Bd. 44 (2023), 4, 040201, S. 1-5
https://doi.org/10.1088/1674-4926/44/4/040201
From a wide band gap to the superconducting proximity effect: Fe on Pb(111). - In: New journal of physics, ISSN 1367-2630, Bd. 25 (2023), 3, 033036, insges. 1-15 S.
Epitaxially grown Fe nanostructures on Pb(111) were studied by low-temperature scanning tunneling microscopy and spectroscopy. The deposited Fe assemblies are classified into two groups according to their electronic behavior close to the Fermi energy. One group exhibits a wide energy gap of 0.7 eV that is independent of the temperature ranging from 5 K to room temperature. These Fe islands indicate the absence of the superconductivity proximity effect in their interior. The other group shows a metallic behavior at the Fermi level. The substrate superconducting phase locally enters into these islands, which is evidenced by a sharp resonance at the Fermi energy presumably signaling Andreev reflection at the magnet-superconductor interface.
https://doi.org/10.1088/1367-2630/acc607
Three-dimensional MoS2 nanosheet structures: CVD synthesis, characterization, and electrical properties. - In: Crystals, ISSN 2073-4352, Bd. 13 (2023), 3, 448, S. 1-14
The proposed study demonstrates a single-step CVD method for synthesizing three-dimensional vertical MoS2 nanosheets. The postulated synthesizing approach employs a temperature ramp with a continuous N2 gas flow during the deposition process. The distinctive signals of MoS2 were revealed via Raman spectroscopy study, and the substantial frequency difference in the characteristic signals supported the bulk nature of the synthesized material. Additionally, XRD measurements sustained the material’s crystallinity and its 2H-MoS2 nature. The FIB cross-sectional analysis provided information on the origin and evolution of the vertical MoS2 structures and their growth mechanisms. The strain energy produced by the compression between MoS2 islands is assumed to primarily drive the formation of vertical MoS2 nanosheets. In addition, vertical MoS2 structures that emerge from micro fissures (cracks) on individual MoS2 islands were observed and examined. For the evaluation of electrical properties, field-effect transistor structures were fabricated on the synthesized material employing standard semiconductor technology. The lateral back-gated field-effect transistors fabricated on the synthesized material showed an n-type behavior with field-effect mobility of 1.46 cm2 V^-1 s^-1 and an estimated carrier concentration of 4.5 × 10^12 cm^-2. Furthermore, the effects of a back-gate voltage bias and channel dimensions on the hysteresis effect of FET devices were investigated and quantified.
https://doi.org/10.3390/cryst13030448
Tetrachromatic vision-inspired neuromorphic sensors with ultraweak ultraviolet detection. - In: Nature Communications, ISSN 2041-1723, Bd. 14 (2023), 2281, S. 1-9
Sensing and recognizing invisible ultraviolet (UV) light is vital for exploiting advanced artificial visual perception system. However, due to the uncertainty of the natural environment, the UV signal is very hard to be detected and perceived. Here, inspired by the tetrachromatic visual system, we report a controllable UV-ultrasensitive neuromorphic vision sensor (NeuVS) that uses organic phototransistors (OPTs) as the working unit to integrate sensing, memory and processing functions. Benefiting from asymmetric molecular structure and unique UV absorption of the active layer, the as fabricated UV-ultrasensitive NeuVS can detect 370 nm UV-light with the illumination intensity as low as 31 nW cm^-2, exhibiting one of the best optical figures of merit in UV-sensitive neuromorphic vision sensors. Furthermore, the NeuVS array exbibits good image sensing and memorization capability due to its ultrasensitive optical detection and large density of charge trapping states. In addition, the wavelength-selective response and multi-level optical memory properties are utilized to construct an artificial neural network for extract and identify the invisible UV information. The NeuVS array can perform static and dynamic image recognition from the original color image by filtering red, green and blue noise, and significantly improve the recognition accuracy from 46 to 90%.
https://doi.org/10.1038/s41467-023-37973-0