Abstract

The paper presents structural and dielectric properties of Polypyrrole-MWCNTs/TiO₂/Al₂O₃/n-Si emphasizing that one of the superior characteristics is the appearance of negative dielectric constant and dielectric loss tangent at both high and low frequencies. It may worth mentioning that the need to develop electronic devices based on new materials combination has motivated the development of such structures as supercapacitors and diodes. The structural characterization of PPy-MWCNTs/TiO₂/Al₂O₃/n-Si was investigated using X-ray diffraction, FTIR, Raman spectroscopy, and scanning electron microscope. The oxide film thickness (d_ox), the density of state (N_SS), admittance (Y_m), electric field (E_m), depletion layer width (W_d), and ΔΦb (eV) were examined using the C⁻² − V relationship. At low frequencies, the values of W_d, Φ_b increase, however as frequency rises, the W_d, N_ss, and R_s decrease. The dielectric constant (ɛ`) takes only negative values at a high frequency of 2x10⁷ Hz, whereas it takes both negative and positive values at frequencies of 10⁷, 100, and 10 Hz. The dielectric loss tangent (tanδ) has positive and negative values at frequencies 10⁷, 10⁶, 100, and 10 Hz.

摘要

本文介绍了聚吡咯-多壁碳纳米管/TiO ₂ /Al ₂ O ₃ /n-Si 的结构和介电特性，强调其优越特性之一是在高频和低频下均呈现负介电常数和介电损耗角正切。值得一提的是，基于新材料组合开发电子器件的需求推动了超级电容器和二极管等结构的发展。使用X射线衍射、FTIR、拉曼光谱和扫描电子显微镜研究了PPy-MWCNTs/TiO ₂ /Al ₂ O ₃ /n-Si的结构表征。氧化膜厚度（d _ox），态密度（N_SS )、导纳(Y _m )、电场(E _m )、耗尽层宽度(W _d ) 和ΔΦb (eV) 使用C ^-2 - V 关系进行检查。在低频下，W _d、Φ _b的值增加，但是随着频率升高，W _d、N _ss和R _s减小。介电常数 (ɛ`) 在 2x10 ⁷ Hz 的高频下仅取负值，而在 10 ⁷、100 和 10 Hz 的频率下取负值和正值。介电损耗角正切 (tanδ) 在频率 10 ⁷ , 10处具有正值和负值^6、100和 10 Hz。