MnS thin films prepared by a simple and novel nebulizer technique: report on the structural, optical, and dispersion energy parameters

摘要

The present work describes different properties of manganese sulfide (MnS) thin films deposited on glass substrate at 300 ℃ by a simple and novel nebulized spray technique. The annealing temperature induced enhancement in polycrystalline nature of films was observed from the X-ray diffraction study. The maximum optical trans-mittance of 98 % was observed for the as-deposited thin film. The observed transmittance threshold shift towards higher wavelength region (red shift), indicated a systematic reduction in optical band gap (E_g; 3.95-3.33 eV) of the films with increasing annealing temperature. The increase in Urbach energy with annealing temperature is due to the presence of localized states, which is consistent with the E_g data. The optical constants, dielectric parameters, porosity, dispersion energy parameters, relaxation time, and optical non-linear susceptibility of the films were also evaluated from the optical transmittance data. These results are discussed and correlated well in the light of possible mechanisms underlying the phenomena. The Raman spectra show two peaks at 355 and 637 cm~(-1) which correspond to the vibrations of Mn-S bonds. The strong band edge emission observed in the PL spectra indicates the high optical quality of deposited MnS thin films. The paramagnetic behavior of the film was confirmed from the M-H plot.