Growth and characterization of vacuum evaporated MgSe thin films

Herein, thin flms of magnesium selenide are thermally grown in a vacuum deposition (VD) system onto glass substrates under a vacuum pressure of 10–5 mbar. The flms are structurally, morphologically, compositionally, and optically characterized. It is observed that MgSe thin flms coated by the VD technique are composed of polycrystalline MgSe1.07 (a=5.149 ?, space group Fm3m) and MgSe1.96 (a=6.514 ?, space group P3?a) cubic phases. The flms displayed an average roughness value of 13 nm. They also exhibited a direct energy band gap of 2.54 eV and an indirect band gap of 3.34 eV. In addition, detailed studies of the dielectric properties, optical conductivity, and terahertz cutof frequency spectra showed the ability of MgSe thin flms to perform as a dielectric material. High dielectric constant values are reached in the near-infrared range of light. As optical conductors, the flms displayed one IR, two visible, and two ultraviolet light oscillators showing a maximum plasmon frequency of 8.19 GHz in the UV range. The drift mobility of these oscillators varied in the range of 4.57–9.67 cm2 / Vs. Moreover, the terahertz cutof frequency for these oscillators varied in the range of 11–175 THz proofng the suitability of MgSe flms for terahertz technology issues.