The investigation of frequency dependent dielectric properties and ac conductivity by impedance spectroscopy in the Al/(Cu-doped Diamond Like Carbon)/Au structures

In order to perform metal-interlayer-semiconductor (MIS) Schottky diodes (SDs) with a greater barrier height (BH), various materials are used at M/S interface as interlayer. Here, the interlayer material's characteristics are crucial, notably the need for characteristics like substrate adhesion, thermal-stability, and low-resistance. Due to its exceptional qualities, diamond-like carbon (DLC), one of the favored materials, was chosen in this investigation. To create the Al/(Cu-DLC)/p-Si/Au MIS type SD in this case, a copper-doped diamond-like carbon (Cu-DLC) nanocomposite film was electrochemically formed as an interlayer. Scanning electron microscopy (SEM) was also used to evaluate the electrodeposited (Cu-DLC) film. The impedance spectroscopy (IS) technique was used to analyze the real-imaginary components of complex dielectric (ε′, ε″) and electric modulus (M′, M″), tangent-loss \((\mathrm{tan}\delta )\) and ac electrical conductivity \(({\sigma }_{ac})\) in wide range of frequency (3 kHz–3 MHz) and voltage (± 4.0 V). All these parameters derived from the impedance-measurements were found strong function of frequency and voltage at low-moderate frequencies due to a unique distribution of surface states \({(N}_{ss})\) at (Cu-DLC)/p-Si interface and interfacial/dipole polarizations. As frequency rises, M′ and M″, values rise while ε′ and ε″ values decrease.