Electric and dielectric parameters in Au/n-Si (MS) capacitors with metal oxide-polymer interlayer as function of frequency and voltage

• Published in: Journal of materials science. Materials in electronics 2020-09, Vol.31 (18), p.15589-15598
• Main Authors: Demirezen, Selçuk, Eroğlu, Ayşegül, Azizian-Kalandaragh, Yashar, Altındal, Şemsettin
• Format: Article
• Language: English
• Subjects: Accumulation; Capacitors; Characterization and Evaluation of Materials; Chemistry and Materials Science; Depletion; Dielectric properties; Diffusion barriers; Dipoles; Electric fields; Electric potential; Electrical resistivity; Energy storage; Gold; Interlayers; Magnesium oxide; Materials Science; Metal oxides; Optical and Electronic Materials; Parameters; Polarization; Polymers; Resistance; Silicon dioxide; Thin films; Voltage
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-04122-y

In the present work, Au/(MgO-PVP)/ n -Si (MPS) capacitors were fabricated and their electric and dielectric parameters were examined via impedance spectroscopy method (ISM) and compared with each other between – 2 and 3 V biases and 10 kHz/5 MHz frequencies. Both the capacitance ( C ) and conductance ( G / ω ) values have large dispersion in inversion, depletion, and accumulation regions due to the existence of surface states/traps ( N ss / D it ), interface/dipole polarizations, series resistance ( R s ), and (MgO-PVP) organic interlayer. Among them, N ss and polarization are effective in inversion and depletion regions at low–intermediate frequencies, but R s and interlayer are effective only at accumulation region at high frequencies. The voltage and frequency-dependent N ss and R s were extracted from the Hill–Coleman and Nicollian–Brews methods, respectively. Some basic electrical parameters such as diffusion potential ( V D ), Fermi energy ( E F ), depletion region width ( W D ), and barrier height ( Φ B ) were calculated from the intercept and slope of the linear regimes C −2 – V curves as function of frequency. Additionally, the real and imaginary parts of complex dielectric constant ( ε * ), complex electric modulus ( M * ), and ac conductivity ( σ ac ) were extracted from the C and G/ω data as function of frequency and voltage. The ε' value of the (MgO-PVP) interlayer was found as 5.0 even at 10 kHz which is very high when compared conventional insulator layer by traditional method such as SiO 2 above 10 kHz in respect of easy grown processes, low cost, flexibility and high mechanical strength. These results show that the used (MgO-PVP) polymer interlayer leads to a large polarization and more storage charges/energy in the MPS-type capacitors rather than MOS capacitors.