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Probing the light hole / heavy hole switching with correlated magneto-optical spectroscopy and chemical analysis on a single quantum dot
摘要： A whole series of complementary studies have been performed on the same, single nanowire containing a quantum dot: cathodoluminescence spectroscopy and imaging, micro-photoluminescence spectroscopy under magnetic field and as a function of temperature, and energy-dispersive X-ray spectrometry and imaging. The ZnTe nanowire was deposited on a Si3N4 membrane with Ti/Al patterns. The complete set of data shows that the CdTe quantum dot features the heavy-hole state as a ground state, although the compressive mismatch strain promotes a light-hole ground state as soon as the aspect ratio is larger than unity (elongated dot). A numerical calculation of the whole structure shows that the transition from the heavy-hole to the light-hole configuration is pushed toward values of the aspect ratio much larger than unity by the presence of a (Zn,Mg)Te shell, and that the effect is further enhanced by a small valence band offset between the semiconductors in the dot and around it.
关键词： molecular beam epitaxy,optical spectroscopy,EDX,semiconductors,cathodoluminescence,quantum dot,nanowires
更新于2025-11-21 11:20:48
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Synthesis of hybrid zinc-based materials from ionic liquids: a novel route to prepare active Zn catalysts for the photoactivation of water and methane
摘要： A new and simple route for the preparation of zinc-based materials is proposed in this work. The synthesis of zinc oxide from the hydrolysis of imidazolium trichlorozincate ionic liquids (ILs) produces catalytic active nanostructured materials, where the size and shape (irregular particles, nanorods) are dependent on the synthetic conditions employed. Indeed, the hydrolysis of trichlorozincate ILs prepared by an equimolar ionic liquid:ZnCl2 ratio afforded irregular particles, while increasing the IL amount (2:1 and 4:1) drives to the formation of nanorods. These hybrid zinc oxide materials were able to promote the photoactivation of water and methane at 25 °C affording up to 1417 μmolH2.g-1.h-1 and up to 67 μmolCO2.g-1.h-1, respectively. Moreover, tuning the reaction conditions a microstructured zinc-based mineral named simonkolleite was prepared with the expected hexagonal-like morphology. This compound was also applied as an alternative and efficient photocatalyst in the activation of water (972 μmolH2.g-1.h-1) and methane (12.6 μmolCO2.g-1.h-1).
关键词： Zinc oxide,photocatalysis,semiconductors,simonkolleite,ionic liquids,nanomaterials
更新于2025-11-21 11:18:25
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Enhanced Charge Separation in g-C3N4 – BiOI Heterostructures for Visible Light Driven Photoelectrochemical Water Splitting
摘要： Heterojunctions of the low bandgap semiconductor bismuth oxyiodide (BiOI) with bulk multilayered graphitic carbon nitride (g-C3N4) and few layered graphitic carbon nitride sheets (g-C3N4-S) are synthesized and investigated as an active photoanode material for sunlight driven water splitting. HR-TEM and elemental mapping reveals formation of a unique heterostructure between BiOI platelets and the carbon nitride (g-C3N4 and g-C3N4-S) network that consisted of dendritic BiOI nanoplates surrounded by g-C3N4 sheets. The presence of BiOI in g-C3N4-S/BiOI and g-C3N4-S/BiOI nanocomposites extends the visible light absorption profile from 500 nm up to 650 nm. Due to excellent charge separation in g-C3N4/BiOI and g-C3N4-S/BiOI, evident from quenching of the carbon nitride photoluminescence (PL) and a decrease in the PL lifetime, a significant increase in photoelectrochemical performance is observed for both types of g-C3N4-BiOI heterojunctions. In comparison to heterojunctions of bulk g-C3N4 with BiOI, the nancomposite consisting of few layered sheets of g-C3N4 and BiOI exhibits higher photocurrent density due to lower recombination in few layered sheets. A synergistic trap passivation and charge separation is found to occur in the g-C3N4-S/BiOI nanocomposite heterostructure which results in a higher photocurrent and a lower charge transfer resistance.
关键词： visible light driven photocatalysis,earth abundant semiconductor heterostructures,Graphenic semiconductors,photoelectrochemistry
更新于2025-11-21 11:01:37
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Light-Stimulated Synaptic Transistors Fabricated by a Facile Solution Process Based on Inorganic Perovskite Quantum Dots and Organic Semiconductors
摘要： Implementation of artificial intelligent systems with light-stimulated synaptic emulators may enhance computational speed by providing devices with high bandwidth, low power computation requirements, and low crosstalk. One of the key challenges is to develop light-stimulated devices that can response to light signals in a neuron-/synapse-like fashion. A simple and effective solution process to fabricate light-stimulated synaptic transistors (LSSTs) based on inorganic halide perovskite quantum dots (IHP QDs) and organic semiconductors (OSCs) is reported. Blending IHP QDs and OSCs not only improves the charge separation efficiency of the photoexcited charges, but also induces delayed decay of the photocurrent in the IHP QDs/OSCs hybrid film. The enhanced charge separation efficiency results in high photoresponsivity, while the induced delayed decay of the photocurrent is critical to achieving light-stimulating devices with a memory effect, which are important for achieving high synaptic performance. The LSSTs can respond to light signals in a highly neuron-/synapse-like fashion. Both short-term and long-term synaptic behaviors have been realized, which may lay the foundation for the future implementation of artificial intelligent systems that are enabled by light signals. More significantly, LSSTs are fabricated by a facile solution process which can be easily applied to large-scale samples.
关键词： light-stimulated synaptic transistors,solution process,organic semiconductors,blended materials,inorganic halide perovskite quantum dots
更新于2025-11-19 16:56:42
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Multi-scale ordering in highly stretchable polymer semiconducting films
摘要： Stretchable semiconducting polymers have been developed as a key component to enable skin-like wearable electronics, but their electrical performance must be improved to enable more advanced functionalities. Here, we report a solution processing approach that can achieve multi-scale ordering and alignment of conjugated polymers in stretchable semiconductors to substantially improve their charge carrier mobility. Using solution shearing with a patterned microtrench coating blade, macroscale alignment of conjugated-polymer nanostructures was achieved along the charge transport direction. In conjunction, the nanoscale spatial confinement aligns chain conformation and promotes short-range π–π ordering, substantially reducing the energetic barrier for charge carrier transport. As a result, the mobilities of stretchable conjugated-polymer films have been enhanced up to threefold and maintained under a strain up to 100%. This method may also serve as the basis for large-area manufacturing of stretchable semiconducting films, as demonstrated by the roll-to-roll coating of metre-scale films.
关键词： charge carrier mobility,conjugated polymers,solution shearing,stretchable semiconductors,roll-to-roll coating,multi-scale ordering
更新于2025-11-19 16:56:35
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A high-performance photocatalyst of ZnTCPP sensitized porous graphitic carbon nitride for antibiotic degradation under visible light irradiation
摘要： In this paper, a highly efficient photocatalyst of ZnTCPP sensitized g-C3N4 was successfully constructed via a facile thermal polycondensation method. The FT-IR and XRD data indicated that ZnTCPP molecules were successfully condensed on the surface of g-C3N4 through amide groups as the bridging units. The optimum 10%ZnTCPP/g-C3N4 composites exhibits excellent enhanced photocatalytic activity for decomposing both methylene blue (MB) and tetracycline (TC) under visible light with long-term reusability and elimination rates of 96% and 80.3%, respectively. The superior visible light photocatalytic performance was mainly attributed to the highly efficient separation of electron-hole pairs and the enhanced solar light utilization, as demonstrated by photoluminescence (PL), electrochemical impedance spectra (EIS), photocurrent responses, and UV-vis diffuse reflectance spectroscopy (DRS). The active species trapping and terephthalic acid (TA) fluorescence experiments indicated that ·OH was the dominating reactive oxidizing species for TC degradation. Furthermore, the possible photocatalytic degradation pathways for MB and TC have been proposed based on the UPLC-MS spectrometry. The excellent degradation efficiency of ZnTCPP/g-C3N4 reveals that it has great potential as photocatalysts for practical application to eliminate recalcitrant organic contaminants.
关键词： Zn meso-tetra (4-carboxyphenyl) porphyrin,Tetracycline,Photocatalyst,Semiconductors,g-C3N4
更新于2025-11-19 16:46:39
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UV-activated porous Zn2SnO4 nanofibers for selective ethanol sensing at low temperatures
摘要： Porous ternary Zn2SnO4 nanofibers with a high surface-to-volume ratio were fabricated through an electrospinning technique. UV-activated ethanol sensing responses at low temperatures were revealed using these porous Zn2SnO4 nanofibers as a sensing active layer. The ethanol response was up to 32.5, and the calculated detection limit was as low as 1.6 ppm at a low temperature of 130 °C. The sensor exhibited good ethanol selectivity and stability under UV irradiation. The photoinduced electrons reacted with the absorbed oxygen molecules to form active O? species [O?(hν)], which contributed to the enhanced resistance modulation and low-temperature ethanol response of Zn2SnO4 nanofibers.
关键词： Zn2SnO4,Semiconductors,Electrospinning,UV irradiation,Sensors
更新于2025-11-14 17:04:02
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Addressing the Reliability and Electron Transport Kinetics in Halide Perovskite Film via Pulsed Laser Engineering
摘要： The long-term performance and stability of perovskites are adversely affected by their porous microstructure, tensile residual stress, and electron transport kinetics. Here, a high-speed pulsed laser processing technique is implemented to produce beneficial structural changes in organic–inorganic halide perovskites, including pore-free, crystalline structure, reduced defects, and tensile residual stress. Moreover, halide perovskite films can be converted from p-type to n-type semiconductor, which originates from crystal structure changes, giving rise to carrier dynamic changes. Comparing with traditional thermal annealing, residual tensile stress of perovskite thin film decreases by 40% after pulse laser processing, which significantly increases its stability. Pulse-laser-induced thermomechanical shock momentum can create pore-free perovskite thin films, contributing to much better reliability. Under humidity of 80% at room temperature for 500 h, the decomposition rate is reduced by more than two times, comparing thin films after pulsed laser processing with conventional thermal annealing. The thermal decomposition temperature of pulse-laser-processed perovskite thin film raises by 20 to about 220 °C. Pulse laser processing technique provides a scalable technique to tailor the structures in perovskite films with both temperature and loading control, further facilitates the design of perovskite-based devices for service under harsh conditions, and also contributes to high-performance optoelectronic applications.
关键词： semiconductors,perovskites,stability,microstructures,residual stress
更新于2025-11-14 15:24:45
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High-Mobility Inkjet-Printed Indium-Gallium-Zinc-Oxide Thin-Film Transistors Using Sr-Doped Al2O3 Gate Dielectric
摘要： In this paper, we demonstrate high-mobility inkjet-printed indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) using a solution-processed Sr-doped Al2O3 (SAO) gate dielectric. Particularly, to enhance to the electrical properties of inkjet-printed IGZO TFTs, a linear-type printing pattern was adopted for printing the IGZO channel layer. Compared to dot array printing patterns (4 × 4 and 5 × 5 dot arrays), the linear-type pattern resulted in the formation of a relatively thin and uniform IGZO channel layer. Also, to improve the subthreshold characteristics and low-voltage operation of the device, a high-k and thin (~10 nm) SAO film was used as the gate dielectric layer. Compared to the devices with SiO2 gate dielectric, the inkjet-printed IGZO TFTs with SAO gate dielectric exhibited substantially high field-effect mobility (30.7 cm2/Vs). Moreover, the subthreshold slope and total trap density of states were also significantly reduced to 0.14 V/decade and 8.4 × 1011/cm2·eV, respectively.
关键词： metal-oxide semiconductors,thin-film transistors,high-k dielectric,high mobility,inkjet printing
更新于2025-11-14 15:19:41
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Anisotropic infrared light emission from quasi-one-dimensional layered TiS<sub>3</sub>
摘要： Atomically thin semiconductors hold great potential for nanoscale photonic and optoelectronic devices because of their strong light absorption and emission. Despite progress, their application in integrated photonics is hindered particularly by a lack of stable layered semiconductors emitting in the infrared part of the electromagnetic spectrum. Here we show that titanium trisulfide (TiS3), a layered van der Waals material consisting of quasi-one-dimensional chains, emits near infrared light centered around 0.91 eV (1360 nm). Its photoluminescence exhibits linear polarization anisotropy and an emission lifetime of 210 ps. At low temperature, we distinguish two spectral contributions with opposite linear polarizations attributed to excitons and defects. Moreover, the dependence on excitation power and temperature suggests that free and bound excitons dominate the excitonic emission at high and low temperatures, respectively. Our results demonstrate the promising properties of TiS3 as a stable semiconductor for optoelectronic and nanophotonic devices operating at telecommunication wavelengths.
关键词： infrared luminescence,transition metal trichalcogenides,titanium trisulfide,linear polarization anisotropy,layered semiconductors
更新于2025-11-14 14:32:36