Suppressing the intrinsic photoelectric response of organic semiconductors for highly-photostable organic transistors. - In: Small, ISSN 1613-6829, Bd. 19 (2023), 50, 2304634, S. 1-8
Suppressing the photoelectric response of organic semiconductors (OSs) is of great significance for improving the operational stability of organic field-effect transistors (OFETs) in light environments, but it is quite challenging because of the great difficulty in precisely modulating exciton dynamics. In this work, photostable OFETs are demonstrated by designing the micro-structure of OSs and introducing an electrical double layer at the OS/polyelectrolyte dielectric interface, in which multiple exciton dynamic processes can be modulated. The generation and dissociation of excitons are depressed due to the small light-absorption area of the microstripe structure and the excellent crystallinity of OSs. At the same time, a highly efficient exciton quenching process is activated by the electrical double layer at the OS/polyelectrolyte dielectric interface. As a result, the OFETs show outstanding tolerance to the light irradiation of up to 306 mW&hahog;cm−2, which far surpasses the solar irradiance value in the atmosphere (≈138 mW&hahog;cm−2) and achieves the highest photostability ever reported in the literature. The findings promise a general and practicable strategy for the realization of photostable OFETs and organic circuits.
https://doi.org/10.1002/smll.202304634
Bimetallic-based composites for potassium-ion storage: challenges and perspectives. - In: Inorganic chemistry frontiers, ISSN 2052-1553, Bd. 10 (2023), 16, S. 4668-4694
Potassium ion batteries (PIBs) are important for the development of energy storage systems as an effective complement to lithium ion batteries (LIBs) owing to the abundance of potassium resources in the earth's crust to meet the needs of large-scale energy storage systems. To this end, numerous studies have focused on anode materials, which can provide high capacity for PIBs. Bimetallic-based compounds (ABXs) achieve higher capacity and structural diversity due to their different chemical compositions and rich spatial structures. Moreover, the synergistic effect of the two metals makes the structure of ABXs more stable. Hence, ABXs are one of the most promising anode materials. This review focuses on performance optimization strategies (such as metal base selection, structural design, voltage regulation, and electrolyte optimization) and the electrochemical properties of ABXs. Finally, the current challenges and research prospectives of ABXs are presented. This review is expected to provide new perspectives and deeper insights into the study of ABXs as anode materials for PIBs and large-scale energy storage devices.
https://doi.org/10.1039/D3QI00585B
Ultrathin metal Ni layer on ZnO/TiO2 photoelectrodes with excellent photoeletrochemical performance in multiple electrolyte solutions. - In: Fuel, ISSN 1873-7153, Bd. 351 (2023), 128774
It is well known that the oxygen vacancy (Ovac) as the electron-donor dopant in semiconductor can increase the electron-holes separation in photoeletrochemical (PEC) water splitting. Furthermore, the metal Ni can promote the hydrogen evolution reaction (HER) on the surface of semiconductor. In this paper, the ZnO/TiO2 photoelectrodes with rich Ovac was synthesized by electrostatic adsorption through using ZIF-8 as the precursor. Then the ultrathin Ni layer with about 7 nm was deposited on the surface of ZnO/TiO2 (Ni/ZnO/TiO2) by vacuum thermal evaporation method. The Ni/ZnO/TiO2 photoelectrodes showed the highest photocurrent than ZnO/TiO2, Ni/ TiO2 and pure TiO2 photoelectrodes. The durability of Ni/ZnO/TiO2 photoelectrodes was keeping for 10 h in multiple electrolyte solutions under AM 1.5 G illumination and the photocurrent decline can be ignored. The UV-vis absorption spectra demonstrated that the ultrathin Ni layer showed plasma with ZnO/TiO2 for enhancing the water splitting performance. Furthermore, the ultrathin Ni layer enhanced the photogenerated charges transfer for improving the PEC performance. This work provides a new method for ultrathin metal Ni layer with Ovac semiconductor photoelectrode to improve the PEC performance in multiple electrolyte solutions.
https://doi.org/10.1016/j.fuel.2023.128774
Visible-light-assisted donor-acceptor-Stenhouse-adduct-based reversible photoswitching on a laser-structurable OrmoComp substrate. - In: ACS applied polymer materials, ISSN 2637-6105, Bd. 5 (2023), 10, S. 8631-8640
Laser-assisted nanolithography of commercially available photoresists is offering a limitless designing opportunity in the micro- and nanostructuring of 3D organotypic cell culture scaffolds. Among them, chemically functionalized OrmoComp has shown promising improvement in cell adhesion that paves the way to assemble cellular entities on a desirable geometry. Establishing a photoswitchable chemistry on the OrmoComp surface may offer an additional degree of freedom to manipulate the surface chemistry locally and selectively. We have established the methods for functionalization of the photopolymerized OrmoComp surface with visible-light-switchable donor-acceptor Stenhouse adducts. Unlike other polymers, a photopolymerized OrmoComp surface appears to be optimal for reversible photothermal switching, offering the possibility to influence surface properties like absorption and hydrophilicity tremendously. Light-assisted chemical modulation between colored triene-2-ol and colorless cyclopentenone can be achieved to a size region as narrow as 20 μm. Thermal reversion to the original triene-2-ol state can be analyzed spectroscopically and observed with the naked eye.
https://doi.org/10.1021/acsapm.3c01766
Gate-tunable hysteresis response of field effect transistor based on sulfurized Mo. - In: AIP Advances, ISSN 2158-3226, Bd. 13 (2023), 9, 095224, S. 095224-1-095224-7
Hysteresis effects and their tuning with electric fields and light were studied in thin film molybdenum disulfide transistors fabricated from sulfurized molybdenum films. The influence of the back-gate voltage bias, voltage sweep range, illumination, and AlOx encapsulation on the hysteresis effect of the back-gated field effect transistors was studied and quantified. This study revealed the distinctive contribution of MoS2 surface, MoS2/SiO2 interface defects and their associated traps as primary sources of of hysteresis.
https://doi.org/10.1063/5.0165868
Research progress of solid electrolyte interphase for sodium metal anodes. - In: The chemical engineering journal, ISSN 1873-3212, Bd. 475 (2023), 146227
Inhomogeneous and fragile solid electrolyte interphase (SEI) leads to poor battery cycle life and safety hazards, which is a key challenge that limits the practical application of low-cost sodium metal anodes. Although sodium metal batteries based on non-aqueous liquid and solid electrolytes have made great progress in terms of interfacial chemistry and SEI regulation strategies, the relevant evaluation of SEI from the perspective of the electrolyte is not well understood. This paper reviews the formation mechanism, physicochemical properties, and failure mechanism of SEI at the interface between the sodium metal and the liquid/solid electrolyte, focusing on poor stability, compatibility, interfacial ion transport problems, and influencing factors. Recent advances in SEI regulation are summarized in terms of electrolytes, artificial interphases, and electrode engineering to achieve ideal electrochemical reversibility. The effectiveness of the SEI engineering strategies was evaluated based on a comprehensive review of the interfacial stability in different electrolyte systems. Finally, the challenges associated with rational interface design for long-lasting sodium metal batteries are discussed, along with promising avenues for the same.
https://doi.org/10.1016/j.cej.2023.146227
High-purity graphene and carbon nanohorns prepared by base-acid treated waste tires carbon via direct current arc plasma. - In: Environmental research, ISSN 1096-0953, Volume 238 (2023), part 1, 117071
As the accumulation of waste tires continues to rise year by year, effectively managing and recycling these discarded materials has become an urgent global challenge. Among various potential solutions, pyrolysis stands out due to its superior environmental compatibility and remarkable efficiency in transforming waste tires into valuable products. Thus, it is considered the most potential method for disposing these tires. In this work, waste tire powder is pyrolyzed at 560 ˚C to yield pyrolysis carbon black, and meanwhile, the purification effects of base-acid solutions on pyrolysis carbon black are discussed. High-purity few-layer graphene flakes and carbon nanohorns are synthesized by a direct current arc plasma with H2 and N2 as buffer gases and high-purity pyrolysis carbon black as raw material. Under an H2 atmosphere, hydrogen effectively terminates the suspended carbon bonds, preventing the formation of closed structures and facilitating the expansion of graphene sheets. During the preparation of carbon nanohorns, the nitrogen atoms rapidly bond with carbon atoms, forming essential C-N bonds. This nitrogen doping promotes the formation of carbon-based five-membered and seven-membered rings and makes the graphite lamellar change in the direction of towards negative curvature. Consequently, such change facilitates the formation of conical structures, ultimately yielding the coveted carbon nanohorns. This work not only provides an economical raw material for efficient large-scale synthesis of few-layer graphene and carbon nanohorns but also broadens the intrinsic worth of pyrolysis carbon black, which is beneficial to improving the recycling value of waste tires.
https://doi.org/10.1016/j.envres.2023.117071
A flexible humidity sensor constructed by ordered-pore-array of slightly reduced graphene oxide with much enhanced sensing response. - In: Surfaces and Interfaces, ISSN 2468-0230, Bd. 41 (2023), 103204
Reduced graphene oxide (rGO) flexible film humidity sensor has received increasing attention, but the low sensing response caused by lack of available hydrophilic functional groups is still a limitation. Herein, a slightly reduced graphene oxide (SrGO) ordered-pore-array, fabricated via a monolayer colloid crystal template method, was introduced as a resistive humidity sensor. It was obtained based on adsorption between the GO sheets and the template microspheres, in-situ slight reduction of the GO shells and the removal of template. The reduction way allows the functional groups of GO to be retained as much as possible, and the unique structures (e.g., spherical double surfaces and small through-holes on pore-walls) facilitate the substantial exposure of functional groups, the penetration of water molecules and the utilization of buried functional groups. The available functional groups are thereby efficiently increased, giving the sensor an unprecedented high sensing response, more than 2600 times the maximum response of existing rGO sensors. The sensor also demonstrated excellent practical characteristics, and by detecting a single exhale, it could be employed in quick and quantitative evaluation of human activities and health. This strategy paves a facile and promising route to improve the sensing response and application of graphene-based humidity sensors or gas sensors.
https://doi.org/10.1016/j.surfin.2023.103204
High thermal stability of the reflectivity of Be/Al multilayer mirrors designed for extreme ultraviolet wavelength. - In: Surfaces and Interfaces, ISSN 2468-0230, Volume 42 (2023), part A, 103404
Superior optical contrast due to the combination of beryllium and aluminum in periodic Be/Al multilayers is the reason for effective reflectivity of these mirrors at extreme ultraviolet wavelength i.e. 17 nm. Depending on the thickness of the layers and annealing temperature, microstructure of beryllium and aluminum layers in periodic multilayers was investigated by Raman scattering spectroscopy and X-ray diffraction. Thinner film of beryllium showed more ordered structure which is qualitatively determined by narrow linewidth of optical phonon. The nucleation and grain growth of beryllium and aluminum is observed at higher annealing temperature. However, the effect of annealing on the modification of microstructure of beryllium and aluminum at lower temperature 373 K is not observed. This is the reason for almost similar value of reflectivity of ∼ 55 % for as-deposited and thermally annealed mirror at 373 K. At higher annealing temperature, the complete loss of reflectivity is observed, associated with the destruction of periodic modulation of mirrors due to interdiffusion, nucleation and grain growth of beryllium and aluminum.
https://doi.org/10.1016/j.surfin.2023.103414
Self-induced ultrafast electron-hole-plasma temperature oscillations in nanowire lasers. - In: Physical review applied, ISSN 2331-7019, Bd. 20 (2023), 3, S. 034045-1-034045-12
Nanowire lasers can be monolithically and site-selectively integrated onto silicon photonic circuits. To assess their full potential for ultrafast optoelectronic devices, a detailed understanding of their lasing dynamics is crucial. However, the roles played by their resonator geometry and the microscopic processes that mediate energy exchange between the photonic, electronic, and phononic subsystems are largely unexplored. Here, we study the dynamics of GaAs-AlGaAs core-shell nanowire lasers at cryogenic temperatures using a combined experimental and theoretical approach. Our results indicate that these NW lasers exhibit sustained intensity oscillations with frequencies ranging from 160GHz to 260GHz. As the underlying physical mechanism, we have identified self-induced electron-hole plasma temperature oscillations resulting from a dynamic competition between photoinduced carrier heating and cooling via phonon scattering. These dynamics are intimately linked to the strong interaction between the lasing mode and the gain material, which arises from the wavelength-scale dimensions of these lasers. We anticipate that our results could lead to optimised approaches for ultrafast intensity and phase modulation of chip-integrated semiconductor lasers at the nanoscale.
https://doi.org/10.1103/PhysRevApplied.20.034045