TY  - JOUR
AU  - Lepadatu, Ana-Maria
AU  - Stoica, Toma
AU  - Stavarache, Ionel
AU  - Teodorescu, Valentin Serban
AU  - Buca, Dan
AU  - Ciurea, Magdalena Lidia
TI  - Dense Ge nanocrystal layers embedded in oxide obtained by controlling the diffusion–crystallization process
JO  - Journal of nanoparticle research
VL  - 15
IS  - 10
SN  - 1572-896X
CY  - Dordrecht [u.a.]
PB  - Springer Science + Business Media B.V
M1  - FZJ-2013-06483
SP  - 1981
PY  - 2013
AB  - Amorphous Ge/SiO2 multilayer structures deposited by magnetron sputtering have been annealed at different temperatures between 650 and 800 C for obtaining Ge nanocrystals in oxide matrix. The properties of the annealed structures were investigated by transmission electron microscopy, Raman spectroscopy, and low temperature photoluminescence. The Ge crystallization is partially achieved at 650 C and increases with annealing temperature. Insight of the Ge nanocrystal formation was acquired by comparing two annealing procedures, i.e., in a conventional tube furnace and by a rapid thermal annealing. By rapid thermal annealing in comparison to conventional furnace one, the Ge crystallization process is faster than Ge diffusion, resulting in the formation of more compact layers of Ge nanocrystals with 8–9.5-nm size as Raman spectroscopy reveals. These findings are important to improve the annealing efficiency in the nanocrystals formation for a precise control of their sizes and location in oxide matrix and for the possibility to create systems with interacting nanoparticles for charge or excitonic transfer. The infrared photoluminescence of Ge nanocrystals at low temperatures shows strong emission with two sharp peaks at about 1,000 meV.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000325255600001
DO  - DOI:10.1007/s11051-013-1981-y
UR  - https://juser.fz-juelich.de/record/141289
ER  -