Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/17523
Title: Si nanocrystal-based LEDs fabricated by ion implantation and plasma-enhanced chemical vapour deposition
Author: Perálvarez Barrera, Mariano José
Barreto, Jorge
Carreras, Josep
Morales, A. (Ángel)
Navarro Urrios, Daniel
Lebour, Youcef
Domínguez, Carlos (Domínguez Horna)
Garrido Fernández, Blas
Keywords: Electrònica
Òptica
Òptica quàntica
Matèria condensada
Electronics
Optics
Quantum optics
Condensed matter
Issue Date: 2009
Publisher: IOP Publishing
Abstract: An in-depth study of the physical and electrical properties of Si-nanocrystal-based MOSLEDs is presented. The active layers were fabricated with different concentrations of Si by both ion implantation and plasma-enhanced chemical vapour deposition. Devices fabricated by ion implantation exhibit a combination of direct current and field-effect luminescence under a bipolar pulsed excitation. The onset of the emission decreases with the Si excess from 6 to 3 V. The direct current emission is attributed to impact ionization and is associated with the reasonably high current levels observed in current–voltage measurements. This behaviour is in good agreement with transmission electron microscopy images that revealed a continuous and uniform Si nanocrystal distribution. The emission power efficiency is relatively low, ~10−3%, and the emission intensity exhibits fast degradation rates, as revealed from accelerated ageing experiments. Devices fabricated by chemical deposition only exhibit field-effect luminescence, whose onset decreases with the Si excess from 20 to 6 V. The absence of the continuous emission is explained by the observation of a 5 nm region free of nanocrystals, which strongly reduces the direct current through the gate. The main benefit of having this nanocrystal-free region is that tunnelling current flow assisted by nanocrystals is blocked by the SiO2 stack so that power consumption is strongly reduced, which in return increases the device power efficiency up to 0.1%. In addition, the accelerated ageing studies reveal a 50% degradation rate reduction as compared to implanted structures.
Note: Dept. Electrònica
Note: Versió postprint del document publicat a http://dx.doi.org/10.1088/0957-4484/20/40/405201
It is part of: Nanotechnology, 2009, vol. 20, núm. 40, p. 405201-1-405201-10
Related resource: http://dx.doi.org/10.1088/0957-4484/20/40/405201
URI: http://hdl.handle.net/2445/17523
ISSN: 0957-4484
Appears in Collections:Articles publicats en revistes (Electrònica)
Publicacions de projectes de recerca finançats per la UE

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