Akademik Veri Yönetim Sistemi
Surfaces and Interfaces, cilt.82, 2026 (SCI-Expanded, Scopus)
This study investigates structure–dielectric property correlations in a Au/COOH-functionalized MWCNT/n-6H-SiC/Au Schottky heterojunction designed to achieve tunable dielectric behavior at room temperature. A chemically functionalized multi-walled carbon nanotube (MWCNT) interfacial layer was introduced between Au contacts and an n-type 6H-SiC substrate to elucidate the role of interfacial morphology and structural disorder on charge transport and dielectric response. SEM analysis reveals a dense, entangled MWCNT network forming a uniform interfacial layer with an average thickness of ∼200 ± 20 nm and an average nanotube diameter of ∼15 nm. Raman spectroscopy confirms a defect-rich structure, with an enhanced d -band intensity (ID/IG > 1), indicative of functionalization-induced disorder and dipole formation. Admittance spectroscopy performed over the frequency range of 20 kHz–1 MHz and bias range of −3 V to +3 V exhibits pronounced frequency- and voltage-dependent dielectric behavior characteristic of a metal–insulator–semiconductor configuration. Significant dispersion in dielectric constant, dielectric loss, and loss tangent is observed in both depletion and accumulation regions, arising from the combined effects of interface traps, dipolar reorientation, and Maxwell–Wagner interfacial polarization. Complementary series resistance and electric modulus analyses further reveal frequency-tunable relaxation processes and trap-assisted conduction mechanisms. These findings demonstrate that chemical functionalization of MWCNTs provides an effective interfacial engineering strategy to achieve tunable dielectric responses in wide-bandgap SiC-based heterojunctions, highlighting their potential for advanced room-temperature electronic and interfacial applications.