Negative Capacitance, Negative Resistance in CNT/TiO2/SiO2/p-Si Heterostructure for Light-Emitting Diode Applications

The novel in this article is the appearance of negative capacitance at low frequency in this structure carbon nanotube/TiO2/SiO2/p-Si, which has not been studied yet in terms of its structural, electrical, and dielectric properties. The CNT/TiO2/SiO2/p-Si was synthesized as a metal oxide semiconductor (MOS) structure. The structural, electrical, dielectric, and capacitance were investigated by XRD, I-V, and C-V measurements. Besides the electrical properties, we present here a comprehensive study of capacitance and its variation with frequency, voltage, and temperature. Through this study, we can control and tune the capacitance in terms of its value as well as its signal polarity as positive or negative values the tunneling behavior and negative resistance were realized in I-V measurements. The capacitance vs temperature, voltage, and frequency was explored, it takes positive values reaching its maximum of about 2.12 x 10(-9)-2.4 x 10(-7) F at high frequencies from 2 x 10(7)-10(3) Hz, but at low frequency from 10(3)-10 Hz, it takes high positive and negative values to reach 4 x 10(-3)-5 x 10(-3) F respectively.