Effect of n and p-silicon Substrate on Dielectric Constant, Dielectric Loss Tangent of PPy-MWCNTs/TiO2/Al2O3 Structure

Abstract

Synthesized these novel structures PPy-MWCNTs/TiO2/Al2O3/p-Si and PPy-MWCNTs/TiO2/Al2O3/n- for using in manufactures diodes, sensor, supercapacitors, and electronic devices. The effect of silicon substrate type on electrical and dielectric parameters such as dielectric constant ɛ`, dielectric loss tangent tanδ, Cole –Cole diagram, the width of the depletion layer (Wd), barrier height (Φb), density state of surface (NSS) and series resistance (Rs) of Au/PPy-MWCNTs/TiO2/Al2O3 were discussed in this work. Researchers frequently alter the composite ratio to increase dielectric characteristics; however, in this study, we use a different approach by altering the type of substrate to improve the dielectric and electric properties of the structure. The sign and magnitude of ɛ` and tanδ are affected by the type of silicon substrate, for example, at frequency 2 × 107 Hz, ɛ` for structure on p-Si has both positive and negative value range (-3500 to 200), whereas ɛ` for structure on n-Si exclusively has negative values (-280 to -220). On the other hand, at the same frequency, tanδ has both positive and negative values (-2 to 8) for structure on p-Si, whilst for n-Si has positive values (0.78 to 0.83). At f = 107 Hz, ɛ` has positive values ranging from (0 to 900) for p-Si substrate while for n-Si, ɛ` has both positive and negative values (-500 to 1500).