[7a-PA3-1~17] 3.2 Equipment optics and materials

[7a-PA3-11] Ab initio calculation of optical properties change of Sb₂Te₃ due to the melting

〇Haruyuki Sano¹, Masashi Kuwahara², Goro Mizutani³ (1.NIT Ishikawa College, 2.AIST, 3.JAIST)

Keywords:optical properties, melting, super-resolution

Sb₂Te₃ is used as the best candidate material for the active layer in a super-resolution optical disc. In this study, ab initio calculation of electronic and optical properties of Sb₂Te₃ was carried out for both crystalline and liquid states. The calculated results indicated that due to the melting, a density of states around Fermi level grows so that an energy band gap opening near Fermi level disappears, and consequently a peak attributed to the inter-band transitions also disappears in the dielectric function spectra. The optical absorption at the photon energy of 3.06 eV decreases due to the melting. This decrease of optical absorption was suggested to result in the decrease of the optical transitions around 1.5 eV.