On the Formation of IR-Light-Emitting Ge Nanocrystals in Ge:SiO{sub 2} Films

Journal Article · Sat Sep 15 04:00:00 EDT 2018 · Semiconductors

DOI:https://doi.org/10.1134/S1063782618090233· OSTI ID:22749800

Rui, Zhang ^[1]; Krivyakin, G. K. ^[2]; Antonenko, A. Kh. ^[1]; Stoffel, M.; Rinnert, H.; Vergnat, M. ^[3]

---

1. Novosibirsk State University (Russian Federation)
2. Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences (Russian Federation)
3. Université de Lorraine, Institut Jean Lamour UMR CNRS 7198 (France)

The study is concerned with light-emitting Ge nanocrystals formed during the annealing of Ge{sub x}[SiO{sub 2}]{sub 1–x} films produced by the high-vacuum cosputtering of germanium and quartz targets onto substrates at a temperature of 100°C. In accordance with the conditions of growth, the Ge molar fraction was varied from 10 to 40%. By means of electron microscopy and Raman spectroscopy, amorphous Ge nanoclusters ~4–5 nm in dimensions are detected in as-deposited films with a Ge content higher than 20 mol %. To crystallize amorphous nanoclusters, annealing at temperatures of up to 650°C is used. The kinetics of the crystallization of Ge nanoclusters is studied, and it is established that up to ~1/3 of the amorphous phase is retained in the system, supposedly at the interfaces between nanocrystals and the surrounding amorphous SiO{sub 2} matrix. It is found that, upon annealing in normal atmosphere, germanium nanoclusters are partially or completely oxidized (at a Ge molar fraction of 30% and smaller). An intense infrared photoluminescence signal from quantum-confined Ge nanocrystals and a visible photoluminescence signal defined by defect complexes (oxygen vacancy + excess Ge atoms) are observed.

• OSTI ID: 22749800
• Journal Information: Semiconductors, Journal Name: Semiconductors Journal Issue: 9 Vol. 52; ISSN SMICES; ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
ANNEALING
CRYSTAL GROWTH
ELECTRON MICROSCOPY
FILMS
GERMANIUM
NANOSTRUCTURES
RAMAN SPECTROSCOPY
SILICA
SILICON OXIDES