Study of A.C. conductivity and dielectric behaviour of hydrothermally synthesised molybdenum disulphide

This report presents an experimental study of electric and dielectric properties of hydrothermally synthesised molybdenum disulphide (MoS 2 ) thin films using complex impedance spectroscopy (CIS). The measurements were taken in the bias voltage range 0 V–0.4 V and frequency 40 Hz–10 MHz. The CIS analysis depicts that both grain (bulk) as well as grain boundary effect has a significant role in the conduction mechanism of the compound. The frequency-dependent relaxation peak was observed in the impedance loss spectra with the upward rise in bias voltage. Also, we found that both real ( ε^' ) and imaginary part ( ε^^'^' ) of complex dielectric permittivity, both parts of electrical modulus (M′ and M′′) and AC conductivity of the MoS 2 thin films are highly dependent on frequency. Existence of a single relaxation peak in electrical modulus plot further confirms the bulk effect in conduction. The varying ac conductivity plot with forward dc bias voltage endorses the occurrence of the hopping mechanism in the system, being well described by jump relaxation model (JRM). In short; this detailed study based on CIS shows the dielectric relaxation behaviour of MoS 2 thin film and reflects the hopping induced conduction mechanism.