skip to main content

SciTech ConnectSciTech Connect

Title: Femtosecond laser-induced crystallization of amorphous N-doped Ge{sub 8}Sb{sub 92} films and in situ characterization by coherent phonon spectroscopy

Femtosecond laser-irradiation-induced phase change of amorphous N-doped Ge{sub 8}Sb{sub 92} films is in situ studied by coherent phonon spectroscopy. We have observed that a new coherent optical phonon (COP) mode occurs as laser irradiation fluence reaches certain thresholds, indicating laser-induced phase changes. Additionally, this new phonon mode has also been verified in heat-annealing-crystallized N-doped Ge{sub 8}Sb{sub 92} films, confirming the emergence of laser-irradiation-induced crystallization. By measuring the pump fluence dependence of COP dynamics in laser-crystallized N-doped Ge{sub 8}Sb{sub 92} films, we found that the frequency and lifetime of COP decrease with the increasing of pump fluence, which suggests good crystallinity in laser-crystallized N-doped Ge{sub 8}Sb{sub 92} films. It has also been observed that the crystallization temperature of amorphous N-doped Ge{sub 8}Sb{sub 92} films increases with N-doping content. Our results indicate promising applications of N-doped Ge{sub 8}Sb{sub 92} films in optical phase-change memory devices.
Authors:
; ;  [1] ; ;  [2]
  1. State-Key Laboratory of Optoelectronic Materials and Technology, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)
  2. Functional Materials Research Laboratory, Tongji University, Shanghai 200092 (China)
Publication Date:
OSTI Identifier:
22399408
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 13; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION SPECTROSCOPY; AMORPHOUS STATE; ANNEALING; ANTIMONIDES; COBALT PHOSPHIDES; CONCENTRATION RATIO; CRYSTALLIZATION; DOPED MATERIALS; GERMANIUM COMPOUNDS; LASER RADIATION; LIFETIME; MEMORY DEVICES; NITROGEN; PHONONS; THIN FILMS