skip to main content

SciTech ConnectSciTech Connect

Title: Effect of annealing temperature on the structure and optical parameters of Ge{sub 20}Se{sub 50}Te{sub 30} thin films

Highlights: • The amorphous nature of as prepared Ge{sub 20}Se{sub 50}Te{sub 30} films was confirmed by XRD. • The thermal annealing was found to affect the structure and optical parameter. • Thermal annealing resulted in an appearance of crystalline phases in studied films. • The average particle size increased with increasing the annealing temperature. • The indirect band gap was found to decrease with increasing annealing temperature. - Abstract: Bulk glasses and thin films of Ge{sub 20}Se{sub 50}Te{sub 30} were prepared by melt-quenching and thermal evaporation technique, respectively. The stoichiometry of the composition was checked by energy dispersive X-ray diffraction (EDX), whereas the crystallization was investigated using differential scanning calorimetery (DSC). The effect of heat treatment on the structure transformation of Ge{sub 20}Se{sub 50}Te{sub 30} films was determined by X-ray diffraction (XRD). The XRD results reveal that the as-prepared films are amorphous in nature while the annealed ones show crystalline phases. Further, the average crystallite size, strain, and dislocation density were found to depend on the annealing temperature. The optical transmittance and reflectance of the studied films at different annealing temperatures were measured using spectrophotometer. The optical parameters were calculated as a function of annealing temperature. The optical transition wasmore » found to be allowed indirect transition with optical band gap decreases from 1.69 to 1.41 eV with increasing the annealing temperature from 553 to 633 K.« less
Authors:
Publication Date:
OSTI Identifier:
22475774
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 65; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMORPHOUS STATE; ANNEALING; CALORIMETRY; CHALCOGENIDES; CRYSTAL STRUCTURE; CRYSTALLIZATION; DENSITY; DISLOCATIONS; GLASS; OPTICAL PROPERTIES; SELENIUM COMPOUNDS; SPECTROPHOTOMETERS; STOICHIOMETRY; STRAINS; TELLURIUM COMPOUNDS; THIN FILMS; TRANSFORMATIONS; X-RAY DIFFRACTION