Search

In the case of low-dimensional semiconductor devices, the basic physical properties of materials can be measured through device manufacturing using single crystal synthesis and exfoliation, but for expansion into various application fields, technology that can synthesize the material itself directly on the substrate is needed. For multi-composition low-dimensional semiconductor materials like Nb2Pd3Se8, the physical characteristics of constituent elements differ, making direct growth control on a substrate extremely challenging. This study successfully synthesized Nb2Pd3Se8 wires using different metal precursors (niobium and palladium) through liquid precursor–intermediated chemical vapor deposition (LPI-CVD). By adjusting the concentration of the liquid precursor and the synthesis temperature, the reproducible growth of Nb2Pd3Se8 wires was achieved, ranging in lengths from 2.29 to 15.04 μm. It was confirmed that PdSe2 is initially synthesized at lower temperatures (below 620 °C), and at temperatures above 620 °C, this PdSe2 transforms into Pd17Se15. Nb2Pd3Se8 is synthesized from the Pd17Se15 at these higher temperatures. X-ray diffraction (XRD) analysis revealed that the wires exhibit a preferred orientation along the (210) plane. Electronic device fabrication using these wires demonstrated their application potential as n-type semiconductors. Field-effect transistor (FET) measurements revealed remarkable performance, with an Ion/Ioff ratio of 575 and an electron mobility of 2.03 cm2 V−1 s−1. LPI-CVD provides a promising strategy for synthesizing ternary chalcogenide materials, opening possibilities for exploring diverse ternary phases. This study highlights the importance of controllability, reproducibility, and FET performance in growing Nb2Pd3Se8 wires via the CVD system, thereby paving the way for integrated applications and facilitating mixed-dimensional studies with other nanomaterials. [ABSTRACT FROM AUTHOR]

In the case of low-dimensional semiconductor devices, the basic physical properties of materials can be measured through device manufacturing using single crystal synthesis and exfoliation, but for expansion into various application fields, technology that can synthesize the material itself directly on the substrate is needed. For multi-composition low-dimensional semiconductor materials like Nb2Pd3Se8, the physical characteristics of constituent elements differ, making direct growth control on a substrate extremely challenging. This study successfully synthesized Nb2Pd3Se8 wires using different metal precursors (niobium and palladium) through liquid precursor–intermediated chemical vapor deposition (LPI-CVD). By adjusting the concentration of the liquid precursor and the synthesis temperature, the reproducible growth of Nb2Pd3Se8 wires was achieved, ranging in lengths from 2.29 to 15.04 μm. It was confirmed that PdSe2 is initially synthesized at lower temperatures (below 620 °C), and at temperatures above 620 °C, this PdSe2 transforms into Pd17Se15. Nb2Pd3Se8 is synthesized from the Pd17Se15 at these higher temperatures. X-ray diffraction (XRD) analysis revealed that the wires exhibit a preferred orientation along the (210) plane. Electronic device fabrication using these wires demonstrated their application potential as n-type semiconductors. Field-effect transistor (FET) measurements revealed remarkable performance, with an Ion/Ioff ratio of 575 and an electron mobility of 2.03 cm2 V−1 s−1. LPI-CVD provides a promising strategy for synthesizing ternary chalcogenide materials, opening possibilities for exploring diverse ternary phases. This study highlights the importance of controllability, reproducibility, and FET performance in growing Nb2Pd3Se8 wires via the CVD system, thereby paving the way for integrated applications and facilitating mixed-dimensional studies with other nanomaterials. [ABSTRACT FROM AUTHOR]

Negative photoconductivity (NPC)-based photodetectors offer a new direction for energy-efficient photodetection technologies, featuring low energy consumption and high responsivity. Two-dimensional (2D) materials are particularly promising for implementing NPC due to their large surface area, abundant surface states, and tunable bandgap properties. In this context, 2D Nb 3 Cl 8 , with its unique kagome lattice structure and broad absorption spectrum, has attracted considerable interest. Notably, metal halides such as Nb 3 Cl 8 demonstrate significant potential as NPC materials due to their low anionic and cationic bonding strength, which allows for the formation of vacancy defects with high probability. However, the NPC characteristics of Nb 3 Cl 8 have not been thoroughly investigated. In this study, we fabricated field-effect transistors (FETs) using Nb 3 Cl 8 single crystals synthesized via chemical vapor transport (CVT). These devices exhibited an electron mobility of 4.24 × 10 -3 cm 2 V -1 s -1 and a high I on / I off ratio of 1.42 × 10 4 . Notably, Nb 3 Cl 8 -based photodetectors demonstrated consistent NPC behavior across a wide wavelength range of 400-1050 nm, with a high responsivity of 156.82 mA W -1 at 400 nm. We propose that the trapping effect due to defect levels within the bandgap is the primary cause of this NPC phenomenon. The present findings reveal the unique photodetector properties of Nb 3 Cl 8 and highlight its promise in energy-efficient photodetectors and various optoelectronic applications.

Solution-based processing of van der Waals (vdW) one- (1D) and two-dimensional (2D) materials is an effective strategy to obtain high-quality molecular chains or atomic sheets in a large area with scalability. In this work, quasi-1D vdW Ta 2 Pt 3 Se 8 was exfoliated via liquid phase exfoliation (LPE) to produce a stably dispersed Ta 2 Pt 3 Se 8 nanowire solution. In order to screen the optimal exfoliation solvent, nine different solvents were employed with different total surface tensions and polar/dispersive (P/D) component (P/D) ratios. The LPE behavior of Ta 2 Pt 3 Se 8 was elucidated by matching the P/D ratios between Ta 2 Pt 3 Se 8 and the applied solvent, resulting in N -methyl-2-pyrrolidone (NMP) as an optimal solvent owing to the well-matched total surface tension and P/D ratio. Subsequently, Ta 2 Pt 3 Se 8 nanowire thin films are manufactured via vacuum filtration using a Ta 2 Pt 3 Se 8 /NMP dispersion. Then, gas sensing devices are fabricated onto the Ta 2 Pt 3 Se 8 nanowire thin films, and gas sensing property toward NO 2 is evaluated at various thin-film thicknesses. A 50 nm thick Ta 2 Pt 3 Se 8 thin-film device exhibited a percent response of 25.9% at room temperature and 32.4% at 100 °C, respectively. In addition, the device showed complete recovery within 14.1 min at room temperature and 3.5 min at 100 °C, respectively.