The origin of anomalous peak and negative capacitance on dielectric behavior in the accumulation region in Au/(0.07 Zn-doped polyvinyl alcohol)/n-4H–SiC metal-polymer-semiconductor structures/diodes studied by temperature-dependent impedance measurements. (September 2020)

• Record Type: Journal Article
• Authors: Al-Dharob, Mohammad Hussein; Kökce, Ali; Aldemir, Durmuş Ali; Özdemir, Ahmet Faruk; Altındal, Şemsettin
• Is Part Of: Journal of physics and chemistry of solids. Volume 144(2020)
• Publication Date: 2020-09
• Subjects: Metal/n-4H–SiC structures with zinc-doped polyvinyl alcohol -- Anomalous peak and negative capacitance -- Electric and dielectric properties -- Ac conductivity -- Temperature and voltage dependence; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2020.109523
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Capacitance-voltage-temperature ( C – V - T) and conductance-voltage-temperature ( G / ω - V - T ) measurements of an Au/(0.07 Zn-doped polyvinyl alcohol)/n-4 H –SiC metal-polymer-semiconductor structure were obtained to study the effect of temperature and voltage on dielectric characteristics such as the dielectric constant ( ϵ ′, ϵ ″), loss tangent (tan δ ), electric modulus, and ac conductivity. The experimental results show that the temperature and the bias voltage have a strong effect on the values of C and G / ω . A peak value is observed in the C – V plot in the forward bias voltage region (1.8 V ≤ V ≤ 2.8 V), which then decreases to a negative value for all temperatures in the high forward bias voltage region ( V ≥ 4 V); such weird behavior is known as negative capacitance. C reduces with rising temperature at high forward bias voltage until negative capacitance is reached. On the other hand, G / ω increases with temperature at sufficiently high forward bias. This behavior of C and G / ω can be attributed to an increase in the number of polarization carriers. All these results were obtained for various temperatures at low and high forward bias voltage (0.5 and 6 V), respectively, and show that C, G / ω, ϵ ′, ϵ ″, tan δ, σ ac, and M ″ increase and M ′ decreases at 0.5 V, whereas C, ϵ ′, M ′, and M ″ increase and G / ω, ϵ ″, tan δ, and σ ac decrease at 6 V. Thus, we can say that the dielectric characteristics and ac conductivity of the diode are affected by change of the applied voltage bias and temperature. Highlights: C – V - T and G / ω - V - T measurements of a metal-polymer-semiconductor structure were recorded. The effects of temperature and voltage on dielectric parameters were examined. Anomalous behavior and negative capacitance were found in the accumulation region. Temperature and bias voltage have a strong effect on the values of C and G / ω.