Synthesis and characterisation of curcumin–M (M = B, Fe and Cu) films grown on p-Si substrate for dielectric applications

• Curcumin (Cur–M) coordinated with B, Fe, and Cu ions were synthesised.
• Cur–M films are good transparent insulators (ρ ∼ 109 Ω cm).
• Cur–M films deposited on p-Si can be used to construct MIS structures.
• The leakage current through Cur–M obey Richardson–Schottky mechanism.
• Cur–B is optoelectronic sensitivity material.

Metal-coordinated yellow curcumin was extracted from green natural sources and sublimated in vacuum to prepare thin films on p-Si and glass substrates for dielectric and optical investigations. The synthesised curcumin complexed with the metals boron, iron, and copper powders were crystalline while the prepared films were amorphous. The optical absorption spectrum of the prepared films showed similar two absorption band structure in the visible range. The onset energy of the main optical absorption band of the film was determined using the Tauc technique. The dielectric properties of this material were systematically studied for future 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. The important find is a large optoelectronic sensitivity so that the integral optical responsivity (S∗) reaches ∼1.0 A/W and the electrical conductivity increases under light illumination by ∼400–1000%. Generally, Curcumin metal complex can be used in small-k environmentally friendly production of microelectronic and optoelectronic devices.

Forward I−Vg characteristics of Al/Cur–M/p-Si MIS diodes in dark and under illumination.Figure optionsDownload as PowerPoint slide