Extraction and dielectric properties of curcuminoid films grown on Si substrate for high-k dielectric applications

•The unknown insulating properties of curcuminoid extract are systematically studied.•Optical study gives a bandgap of 3.15 eV and a refractive index of 1.92 at 505 nm.•Turmeric is a high-k environmental friendly material for use in microelectronics.•Curcuminoid extract can be used as insulator of MIS devices with ε′∞≈54.2.ε′∞≈54.2.

Curcuminoids were extracted from turmeric powder and evaporated in vacuum to prepare thin films on p-Si and glass substrates for dielectric and optical investigations. The optical absorption spectrum of the prepared amorphous film was not identical to that of the molecular one, which was identified by a strong wide absorption band in between ∼220 and 540 nm. The onset energy of the optical absorption of the film was calculated by using Hamberg et al. method. The dielectric properties of this material were systematically studied for future eco friendly applications in metal–insulator–semiconductor MIS field of applications. The complex dielectric properties were studied in the frequency range of 1–1000 kHz and was analysed in-terms of dielectric impedance Z*(ω) and modulus M*(ω). Generally, the curcuminoid complex can be considered as a high-k material and can be used in the environmental friendly production of microelectronic devices.