Microphotoluminescence and perfect ordering of SiGe islands on pit-patterned Si(001) substrates.
Nanotechnology
; 22(16): 165302, 2011 Apr 22.
Article
em En
| MEDLINE
| ID: mdl-21393825
ABSTRACT
We show that both the morphology and the optoelectronic properties of SiGe islands growing in the pits of periodically pre-patterned Si(001) substrates are determined by the amount of Ge deposited per unit cell of the pattern. Pit-periods (p) ranging from 300 to 900 nm were investigated, and Ge growth was performed by molecular beam epitaxy (MBE) at temperatures of 690 and 760 °C. The ordered SiGe islands show photoluminescence (PL) emission, which becomes almost completely quenched, once a critical island volume is exceeded. By atomic force and transmission electron microscope images we identify the transition from pyramid-shaped to dome-shaped islands with increasing p. Eventually, the nucleation of dislocations in the islands leads to PL quenching. Below a critical Ge coverage a narrowing and a blue shift of the PL emission is observed, as compared to islands grown on a planar reference area of the same sample.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Silício
/
Nanoestruturas
/
Germânio
/
Medições Luminescentes
Idioma:
En
Revista:
Nanotechnology
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Áustria