Low-frequency electrical noise in nanocomposite material on silicon

We report on observation of low-frequency electrical noise measurements of a hybrid organic/inorganic nanocomposite material in metal-insulator-semiconductor (MIS) structure. The insulating material was LB films of stearic acid embedded with CdS nanoparticles. The current noise power spectral densities have been measured as a function of frequency at low to moderate leakage current at room temperature. The obtained results exhibit a clear 1/f^γ noise-like power spectrum behavior in the frequency range of up to 1 kHz with 1.15 <; γ <; 1.35. The noise magnitude was extracted from the linear curve fitting and was found to decreased as the leakage current exceeded certain value. We believed that the dominant 1/f-noise source at higher leakage current was due to conduction fluctuations and resides in the organic films matrix, which acts as electron-trapping centers.