Premium
Structural and optical properties of phase‐change amorphous and crystalline Ge 1 − x Te x (0 < x < 1) thin films
Author(s) -
Park JunWoo,
Song Misun,
Yoon Seokhyun,
Lim Hyungkwang,
Jeong Doo Seok,
Cheong Byungki,
Lee Hosun
Publication year - 2013
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201228555
Subject(s) - amorphous solid , raman spectroscopy , thin film , materials science , dielectric , analytical chemistry (journal) , ellipsometry , spectroscopy , phase transition , germanium , crystallography , phonon , condensed matter physics , optics , chemistry , silicon , physics , optoelectronics , nanotechnology , chromatography , quantum mechanics
Ge 1 − x Te x thin films were grown using thermal coevaporation deposition. The dielectric functions and the phonon modes of amorphous (a‐) and crystalline (c‐) Ge 1 − x Te x films were measured using spectroscopic ellipsometry and Raman spectroscopy in order to investigate electronic and vibrational properties of these alloys. Using the second derivative spectra of the dielectric functions of a‐Ge 1 − x Te x alloys and the standard critical point (SCP) model, we obtained optical transition energies for the a‐Ge 1 − x Te x alloys. The optical transition energies were not only consistent with the density of states (DOS) reported in the literature, but also provided more detailed structures for the joint density of states (JDOS) of a‐Ge 1 − x Te x .The second derivative spectra of d 2 ε ( E )/d E 2 for amorphous GeTe. The transition energies were estimated using SCP model (short arrows) and were compared to those of photoemission spectroscopy from literature (long arrows).