Journal of Electronic Materials最新文献

The growing demand for advanced DNA sequencing technologies has stimulated the exploration of novel two-dimensional (2D) materials with exceptional physicochemical properties. In this study, the interactions between DNA nucleobases (adenine, thymine, guanine, and cytosine) and 1H-WSe₂ and Janus 1H-WSSe monolayers were investigated using density functional theory with the OpenMX code. The structural, electronic, and optical properties of the nucleobase–substrate systems were systematically analyzed to assess their potential for sequencing applications. Structural relaxation results reveal physisorption behavior, evidenced by minimal bond length changes upon adsorption. Binding energy calculations indicate that guanine exhibits the strongest interaction with 1H-WSe₂ (G > T > A > C), whereas thymine shows the strongest binding on Janus 1H-WSSe (T > A > C = G). Charge density difference and Mulliken population analyses confirm weak charge transfer dominated by van der Waals interactions. Density-of-states analysis demonstrates that adsorption does not alter the semiconducting nature of either substrate, preserving their intrinsic electronic characteristics. Optical analyses reveal anisotropic dielectric responses, where pristine 1H-WSe₂ exhibits zero-crossing energies at approximately 6.29 eV and 7.19 eV for the out-of-plane (E∥c) polarization and 8.37 eV and 9.03 eV for the in-plane (E⊥c) polarization. Janus 1H-WSSe shows slightly higher values at around 6.74 and 7.66 eV (E∥c) and 8.81 and 9.75 eV (E⊥c). These results highlight the fact that both materials maintain high optical responsiveness with tunable plasmonic excitations upon nucleobase adsorption. Overall, monolayer 1H-WSe₂ and Janus 1H-WSSe exhibit stable physisorption and favorable optoelectronic features, making them promising candidates for next-generation DNA sequencing platforms.

Graphical Abstract

In this work, a recessed T-gated AlN/GaN-HEMT with a β-Ga₂O₃ buffer is proposed and compared with conventional buffer configurations, including Fe-doped GaN/AlGaN structures with and without back-barriers (BBs), to evaluate their influence on direct-current (DC) and radiofrequency (RF) performance. The electrostatic analysis of HEMT with β-Ga₂O₃-buffer reveals a peak g_m of 431.5 mS/mm, an I_{d_peak} of 1.90 A/mm, an I_{ds_sat} of 2.42 A/mm, and an f_T of 197.1 GHz owing to better carrier confinement, reduced parasitic effects, minimal buffer leakage, and the high crystalline quality of the β-Ga₂O₃/GaN interface. We investigated the impact of barrier material selection and observed that an AlN barrier offered better performance, attributed to stronger polarization-induced charge, followed by Al_0.83In_0.17N, and Al_x​Ga_1−xN, with a gradual decline as the Al composition decreased. The AlN/GaN/β-Ga₂O₃/β-Ga₂O₃-HEMT with L_g = 40 nm delivered a maximum g_m of 538.5 mS/mm, an I_{d_peak} of 3.22 A/mm, and an f_T of 469.6 GHz, along with an I_{ds_sat} of 3.49 A/mm, benefiting from improved lattice compatibility. Notably, this structure eliminates the need for additional BB layers and AlN nucleation, offering both performance and fabrication advantages. The AlN/GaN/β-Ga₂O₃/SiC-HEMT also delivered competitive performance, providing a compelling combination of thermal conductivity, material stability, and integration feasibility, while remaining cost-effective. These results offer valuable design insights for AlN/GaN-HEMT development and contribute to ongoing efforts toward enhancing GaN-HEMT performance through the integration of ultrawide bandgap (UWBG) β-Ga₂O₃ buffers, making it highly suitable for next-generation 5G/6G wireless infrastructure, sub-THz high-speed communication systems, and advanced radar applications.

Methylammonium lead bromide (MAPbBr₃) nano-suspensions were synthesized through a simple, low-temperature emulsion–demulsion route, offering a scalable alternative to conventional hot-injection or ligand-assisted methods. These nano-suspensions enabled the deposition of uniform MAPbBr₃ thin films on rigid substrates via spin coating. Structural analysis confirmed the formation of a cubic perovskite phase, supported by XRD, Raman spectroscopy, and TEM. The films exhibited a direct bandgap of ~ 2.23 eV and intense, color-stable green photoluminescence centered at 536 nm. AFM revealed a relatively high surface roughness (RMS ~ 111.6 nm), while XPS verified the expected elemental composition and valence states. When integrated onto 380 nm UV chips, the MAPbBr₃ films functioned as efficient down-conversion layers, producing a bright green emission with a high color purity of 94.5% and CIE coordinates of (0.3064, 0.6663). This study demonstrates a facile, solution-processed pathway for perovskite-based green emitters, highlighting their potential as low-cost alternatives to rare-earth phosphors in solid-state lighting applications.

Continuous, painless glucose monitoring is a critical need for over 422 million people living with diabetes worldwide. As a result, non-invasive and conventional approaches to glucose monitoring are increasingly sought after compared to other microanalytical diagnostic tools. Additionally, blood glucose detection can be replaced by continuous glucose monitoring of other human biological fluids (sweat) collected by non-invasive means. In particular, the detection of blood glucose can be replaced by continuous monitoring through alternative, non-invasive methods that collect human biological fluids, such as sweat. This study developed an electrochemical non-enzymatic sensor using a composite of NiFe Prussian blue analogue [NiFe(PBA)] and a novel class of two-dimensional materials, transition metal carbides known as MXenes. Specifically, Mo₃C₂T_x MXene nanoflakes were employed to tailor the electroanalytical behaviour of the sensor for continuous glucose detection in sweat. Electrochemical studies, including cyclic voltammetry and chronoamperometry, were conducted to evaluate the sensor’s performance. The large specific surface area of the NiFe(PBA) nanocubes, combined with the superior electrical conductivity of Mo₃C₂T_x MXene, enabled the development of a high-performance non-enzymatic glucose biosensor. The sensor exhibited enhanced sensitivity of 993.28 μA mM⁻¹ cm⁻² and a low limit of detection (LOD ≈ 1.2 μM), meeting the requirements for effective glucose monitoring in human sweat.

The increasing demand for photodetection with high capacity and low noise for long-haul optical networks has prompted researchers to develop even better heterojunction-based photodetectors. Traditional phototransistors can not meet the strict performance criteria that modern dense wavelength division multiplexing (DWDM) systems impose. This paper presents the design and full performance analysis of a Ge₁₋ₓSnₓ/Ge multiple quantum well (MQW) heterojunction phototransistor for high-speed optical communication, integrating three periods of Ge₀.₈₃Sn₀.₁₇ quantum wells surrounded by Ge₀.₈₇Sn₀.₁₃ barriers, all designed with doping profiles that enhance carrier confinement, responsivity, and gain, while maintaining low dark current. The phototransistor was modeled and simulated using COMSOL Multiphysics TCAD tools to analyze electric field distribution, carrier transport, and doping effects in the Ge₁₋ₓSnₓ/Ge multiple quantum well heterojunction. For the purpose of evaluating the applicability at the system level, the phototransistor was implemented in a 16 × 100 Gbps DWDM system using dual-polarization quadrature phase-shift keying (DP-QPSK) modulation at an aggregate data rate of 1.6 Tbps over a 2000 km fiber link with 50-GHz channel spacing. System performance was evaluated using optical simulations to quantify system performance metrics, including bit error rate (BER), signal-to-noise ratio (SNR), and quality of eye diagrams. Systems using the proposed MQW device showed significant advantages compared to those employing either Ge-on-Si or InGaAs/InP phototransistors, achieving responsivity greater than 6 A/W, bandwidth > 35 GHz, and SNR > 77 dB at 10 GHz. The results demonstrate the great potential of GeSn/Ge MQW heterostructures that extends beyond high-performance photodetector platforms, to include complementary metal–oxide semiconductor (CMOS)-compatible devices that can be used for next-generation long-reach DWDM receiver and integrated photonic circuits.

A multifunctional copper(II) complex, (1H-imidazole-κN³)[4-methyl-2-({[2-oxido-5-(2-phenyldiazen-1-yl)phenyl]methylidene}amino)pentanoato-κ³O,N,O′]copper(II) (IPMPC), was successfully grown as single crystals using the slow evaporation method in methanol. Its monoclinic structure (space group P2₁) was confirmed by single-crystal x-ray diffraction with excellent crystalline perfection (HRXRD; FWHM: 13.5 arcsec). Stable polarization switching was observed in the ferroelectric P–E loop (Pr = 0.95 μC/cm², Ec = 0.9 kV/cm), and magnetic tests showed that the weak antiferromagnetic coupling between Cu(II) centers was predominant. The efficiency of SHG was 1.36× higher than that of KDP. Lattice stability was demonstrated by mechanical testing. IPMPC’s multifunctional optoelectronic and biological potential was highlighted by its powerful antibacterial and anticancer activities, which included suppressing EGFR/PI3K/AKT signaling and exhibiting an IC₅₀ of 37.68 ± 2.17 μg/mL against MCF-7 cells.

We report the first investigation of vacancy-ordered double perovskites Rb₂OsX₆ (X = Cl, Br, I) as lead-free, aqueous-stable photocatalysts. Using accurate TB-mBJ + SOC DFT calculations, we predict direct band gaps tunable from 2.98 eV (Cl) to 1.81 eV (I), enabling the Br and I compounds to absorb ~ 43% of the solar spectrum with coefficients exceeding 10⁵ cm⁻¹. Band-edge positions straddle the water redox potentials in all three materials (CBM: − 0.05 to − 0.21 V, VBM: + 1.63 to + 2.95 V vs,. NHE at pH 0), satisfying the thermodynamic requirement for overall water splitting without external bias—the first achievement among lead-free A₂BX₆ halide perovskites. Rb₂O_SI₆ further meets the thermodynamic threshold for CO₂ → CH₄ reduction. Ultra-low exciton binding energies, light effective masses (0.61–2.25 m₀), and intrinsic aqueous stability conferred by the vacancy-ordered structure ensure efficient charge dynamics and durability, positioning Rb₂OsX₆ as a breakthrough visible-light photocatalyst family.

Gold-coated silicon substrates have become crucial for advancing optoelectronic devices and nanostructures due to their enhanced properties. This study employs an integrated approach combining the finite-difference time-domain (FDTD) method with the two-temperature model-molecular dynamics (TTM-MD) simulation to investigate ultrafast laser ablation. Simulations were performed on Si substrates coated with varying Au coating thicknesses (0, 20, 35 nm) using a 100-fs, 1030 nm-laser at fluences of 50 and 100 mJ/cm² over a 100-ps duration. We analyzed the temporal evolution of density, potential energy, and pressure distribution to reveal the effects of both coating thickness and laser fluence on the ablation mechanism. The results show that the 20-nm and 35-nm Au coatings reduce energy absorption in the Si substrate by 35% and 66%, respectively, compared to bare Si. The Au layer acts as a protective barrier by partially absorbing and reflecting laser energy, which induces localized heating and reduces atomic displacement and potential energy in the underlying Si. The absorbed energy generates mechanical stress within the Au layer, which confines tensile stress transfer to the Si and suppresses microfracturing. Although higher fluence enhances ablation efficiency, it concurrently increases the risk of Si substrate subsurface cracking. This work provides quantitative insights for optimizing laser processing parameters, including laser fluence and coating thickness, for precise nanostructure fabrication.

Graphical Abstract

The present research work investigates the synthesis of Dy³⁺-doped, Tb³⁺-doped, and Dy³⁺/Tb³⁺-co-doped Sr₂ZnSi₂O₇ (SZSi) phosphors using a high-temperature solid-state technique. X-ray diffraction (XRD) analysis showed that the crystal structure of the synthesized SZSi samples matched the Joint Committee on Powder Diffraction Standards (JCPDS) card no. 00-039-0235. Using diffuse reflectance spectroscopy (DRS), the bandgap of co-doped SZSi:Dy³⁺/Tb³⁺ phosphor was determined to be 3.09 eV. Emission spectra from photoluminescence (PL) spectroscopy showed that SZSi:Dy³⁺, SZSi:Tb³⁺, and SZSi:Dy³⁺/Tb³⁺ phosphors were efficiently excited by near-ultraviolet light. As the concentration of Tb³⁺ ions increased, their PL intensity also increased, causing the PL emission intensity of Dy³⁺ ions to drop, representing the energy transfer from Dy³⁺ to Tb³⁺ ions in the host lattice. The correlated colour temperature (CCT) value for the SZSi:Dy³⁺/Tb³⁺ (x = 1.5, y = 2 mol.%) phosphor was 3091 K, whereas the CIE colour coordinates were (0.31793, 0.30735), representing warm white light luminescence. Additionally, with activation energy of 0.236 eV, the synthesized phosphor demonstrated outstanding thermal stability, maintaining 88% of its emission intensity at 150°C. These results demonstrate the potential of the synthesized phosphors as solid-state warm white-light-emitting diode (LED) lighting sources.

A new organic–inorganic hybrid salt, bis(2-carboxypyridin-1-ium) hexachlorostannate(IV) dihydrate ([2-CpyH]₂[SnCl₆]), was synthesized and structurally characterized through single-crystal x-ray diffraction, Hirshfeld surface analysis, and bond valence sum calculations. The compound exhibits a robust three-dimensional hydrogen-bonded framework and columnar packing of [SnCl₆]²⁻ octahedra, which collectively enhance structural stability and electronic polarization. Optical studies reveal a wide bandgap of 4.28 eV and strong blue-violet emission at 386 nm, indicating potential applicability in UV sensing and related photonic technologies. Z-scan measurements demonstrate a notable third-order nonlinear optical susceptibility, χ⁽³⁾ = 1.75 x 10⁻¹¹ esu, arising from combined reverse saturable absorption and self-defocusing behaviour, confirming the suitability of the material for optical limiting and photonic switching applications. Dielectric measurements show pronounced dispersion at low frequencies and stable, low-loss behaviour at high frequencies, supported by efficient dipolar orientation and interfacial polarization. AC conductivity analysis reveals a transition from defect-mediated conduction at low frequencies to hopping-dominated transport at higher frequencies. These combined structural, optical, and dielectric properties highlight [2-CpyH]₂[SnCl₆] as a promising multifunctional material for photonic, optoelectronic, and dielectric device applications.