Synthesis and Characterization of Mercuric Sulfide Nanoparticles Thin Films by Pulsed Laser Ablation (PLA) in Distilled Water (DW)

Thin films of meta-cinnabar mercuric sulfide (β-HgS) nanoparticles (NPs) was prepared by pulsed laser ablation (PLA) utilizing a pellet of cinnabar mercuric sulfide (α-HgS) was immersed in distilled water (DW). Q-switched Nd:YAG laser of 1064 nm wavelengths with repetition rate (1 Hz) and fluency (1.5 J/ cm2) applied for ablation. Structural, morphological, and particle sizes of the β-HgS NPs are investigated by analyzing XRD, AFM, SEM, and TEM measurements. Their crystal structure is transformed from hexagonal (wurtzite) of the α-HgS target material to cubic (zinc blende) β-HgS NPs. The optical properties of the β-HgS NPs are measured by UV–visible spectrophotometer. The direct bandgap is calculated to be (2.45 eV) of small particles (4-6.2 nm) moreover, the bandgap value of smallest particles (1-4 nm) is (3.47 eV) according to the optical transmission spectra.