Erbium emission in MOS light emitting devices: from energy transfer to direct impact excitation

• Published in: Nanotechnology Vol. 23; no. 12; p. 125203
• Main Authors: Ramírez, J M, Ferrarese Lupi, F, Jambois, O, Berencén, Y, Navarro-Urrios, D, Anopchenko, A, Marconi, A, Prtljaga, N, Tengattini, A, Pavesi, L, Colonna, J P, Fedeli, J M, Garrido, B
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 30.03.2012; Institute of Physics (IOP)
• Subjects: Compostos de silici; Devices; Electric potential; Emission; Energy transfer; Erbium; Excitation; Metal oxide semiconductors; Metall-òxid-semiconductors; Nanostructure; Silicon compounds; Transferència d'energia
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/23/12/125203

The electroluminescence (EL) at 1.54 µm of metal-oxide-semiconductor (MOS) devices with Er3+ ions embedded in the silicon-rich silicon oxide (SRSO) layer has been investigated under different polarization conditions and compared with that of erbium doped SiO2 layers. EL time-resolved measurements allowed us to distinguish between two different excitation mechanisms responsible for the Er3+ emission under an alternate pulsed voltage signal (APV). Energy transfer from silicon nanoclusters (Si-ncs) to Er3+ is clearly observed at low-field APV excitation. We demonstrate that sequential electron and hole injection at the edges of the pulses creates excited states in Si-ncs which upon recombination transfer their energy to Er3+ ions. On the contrary, direct impact excitation of Er3+ by hot injected carriers starts at the Fowler-Nordheim injection threshold (above 5 MV cm−1) and dominates for high-field APV excitation.