Red electroluminescence in Si+-implanted sol-gel-derived SiO2 films

Citation
K. Luterova et al., Red electroluminescence in Si+-implanted sol-gel-derived SiO2 films, APPL PHYS L, 77(19), 2000, pp. 2952-2954
Citations number
13
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
00036951 → ACNP
Volume
77
Issue
19
Year of publication
2000
Pages
2952 - 2954
Database
ISI
SICI code
0003-6951(20001106)77:19<2952:REISSS>2.0.ZU;2-N
Abstract
We report on a continuously emitting electroluminescent device fabricated b y Si+-ion implantation and subsequent annealing of a SiO2 layer on a silico n substrate. The SiO2 layer with a thickness of 250 nm was prepared by the sol-gel technique. Four different Si+-ion energies and implantation doses w ere applied in order to obtain a flat Si+-ion profile across the SiO2 film thickness with an atomic Si excess of 5%. Electroluminescence (EL) occurs a bove a low-voltage threshold (similar to5 V, 1 A/cm(2)) at one bias polarit y only even if the device in fact does not exhibit rectifying properties. E L microscopy reveals that EL at 295 K is emitted from a small number of bri ght spots with diffraction-limited size. EL spectra of individual bright sp ots were measured using an imaging spectrometer. The wide EL emission band (situated in the red region similar to 750 nm) obtained with spatial averag ing over the semitransparent indium-tin-oxide contact represents the envelo pe of these individual contributions. We suggest that the EL is due to elec tron-hole injection into Si nanocrystals which create several conductive pe rcolation paths across the SiO2 film. Shunting current paths due to defects exist in parallel and are probably the main factor responsible for low EL efficiency (10(-5)%). (C) 2000 American Institute of Physics. [S0003-6951(0 0)01545-X].