What question did this study set out to answer?

This research aims to explore the enhanced field emission properties of MgO/r-GO hybrid nanostructures through experimental and theoretical analyses.

May 31, 2026

Synergistic Enhancement of Electric Field Emission Performance in MgO/r-GO Hybrid Nanostructures: A Correlated DFT Study with Experimental Observation

Key Points

This research aims to explore the enhanced field emission properties of MgO/r-GO hybrid nanostructures through experimental and theoretical analyses.
Conducted experimental observations using X-ray diffraction, Raman spectroscopy, FTIR, and UV-DRS.
Performed density functional theory (DFT) analysis to investigate electronic structures and work function.
Analyzed morphological features using field emission scanning electron microscopy (FESEM).
Turn-on field observed at 2.4 V/μm @ 1 μA/cm2, indicating efficient emission.
Emission current density achieved was 1845 μA/cm2 @ 6.7 V/μm, demonstrating significant improvement.
DFT results showed work function reduction from ∼5.01 eV (MgO) to ∼4.51 eV (MgO/r-GO), enhancing electron emission efficiency.

Abstract

In this study, we focused on the synergistic enhancement in the field emission performance of MgO/r-GO hybrid nanostructures, supported by a comprehensive correlation between experimental observation and density functional theory (DFT) analysis. Structural investigation by X-ray diffraction (XRD) refinement confirms the cubic rock-salt phase of MgO and the successful integration of r-GO (2θ = 24.2°). Raman spectra of the composites indicate the signature D, G, and 2D bands of r-GO, with two minor defect-induced vibrational bands at 277 cm–1 and 442 cm–1 of Mg(OH)2. The Fourier transform infrared (FTIR) spectra elucidate the chemical bonding and functional groups, while UV-DRS spectra exhibit a bandgap modulation from 5.24 to 3.02 eV due to the strong hybridization. Morphological analysis using field emission scanning electron microscopy (FESEM) demonstrates a dispersed network of MgO nanoparticles on r-GO sheets, which offers a high surface area and efficient emission sites. The MgO/r-GO hybrid nanostructure exhibits enhanced field emission performance, evidenced by a lower turn-on field (2.4 V/μm @ 1 μA/cm2), increased emission current density (1845 μA/cm2 @ 6.7 V/μm), and preliminary indication of long-term stability over a long period of ∼4 h, due to improved electrical conductivity, a reduced work function, and effective charge transfer at the MgO/r-GO interface. The DFT study determined the local work function (φ) to be ∼5.01 eV for MgO and ∼4.51 eV for MgO/r-GO composites, and the field enhancement factor (β) was calculated to be 2348 and 3250 for MgO and MgO/r-GO composite field emitters, respectively. The observed density of states indicates charge redistribution near the Fermi level and modifications of the electronic structure, which recommend the potential of MgO/r-GO hybrids for advanced electron emission applications. The experimental and theoretical findings recommend that the MgO/r-GO hybrids are promising for advanced electron-emission applications in vacuum and nanoelectronics.

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Cite This Study

Karmakar et al. (Thu,) studied this question.

synapsesocial.com/papers/6a1bd0155783ba022b6fbdca https://doi.org/https://doi.org/10.1021/acsaenm.6c00405

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