The study of structural changes of amorphous Ge2Sb2Te5films after annealing by optical absorption spectroscopy

✍ Scribed by Gotoh, Tamihiro ;Kawarai, Kenta

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 204 KB
• Volume: 207
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200982754

✦ Synopsis

Abstract

Optical absorption spectra of post‐annealed Ge~2~Sb~2~Te~5~ films were measured in the photon energy range from 0.5 to 3.5 eV. Optical absorption edge and Urbach slope parameter changed slightly with increase in annealing temperature and then abrupt changes occurred at around crystallization temperature. The band gaps of amorphous and cubic Ge~2~Sb~2~Te~5~ are 0.74 and 0.54 eV, respectively. The spectroscopic method is demonstrated to be suitable for evaluation of structural disorder and crystalline composition in phase‐change materials.