Surface characterization and electronic structure of HgTe nanocrystalline thin films

Mercury telluride (HgTe) nanocrystalline thin films were synthesized using an electrochemical deposition technique. The surface morphology of the thin films were investigated by atomic force microscopy (AFM) as a function of the film thickness which shows that an increase in film thickness increases the surface roughness. The scaling exponents such as roughness exponent, α and growth exponent, β associated with the film growth, determined from surface and power spectral analysis using AFM are found to be 0.88±0.05 and 0.21±0.04 respectively. The shifting of the valence and core levels to higher binding energy as evidenced from x-ray photoelectron spectroscopy, suggest the change in electronic structure of the nano-HgTe films possibly due to the surface roughness.