Electroluminescence at 1.54 μm in Er-doped Si nanocluster-based devices

Abstract

The electroluminescence (EL) properties of Er-doped Si nanoclusters (NC) embedded in metal–oxide–semiconductor devices are investigated. Due to the presence of Si NC dispersed in the SiO2 matrix, an efficient carrier injection occurs and Er is excited, producing an intense 1.54 μm room temperature EL. The EL properties as a function of the current density, temperature, and time have been studied in detail. We have also estimated the excitation cross section for Er under electrical pumping, finding a value of ∼1×10−14 cm2. This value is two orders of magnitude higher than the effective excitation cross section of Er ions through Si NC under optical pumping. In fact, quantum efficiencies of ∼1% are obtained at room temperature in these devices.

Polarization strategies to improve the emission of Si-based light sources emitting at 1.55 μm

“…(5) has been used to estimate the absorption cross sections from 30 V and above, where decay > rise obtaining a abs = 4 × 10 −13 cm 2 with a ˇ = 0.8 for Sincs and abs = 5 × 10 −14 cm 2 for Er 3+ ions. Therefore, the absorption cross-section of Si-ncs is 8 times higher than the one of erbium ions, in agreement with previous works [32], which have reported a difference of 5 times between them.…”

“…3, the absorption cross-section was estimated in visible (D1) and infrared (D3) LEDs taking into account a nearly two level system, which has been used by many authors before [31,32]. Starting from the dynamic rate equation, …”

Silicon nanocluster-sensitized emission from erbium: The role of stress in the formation of silicon nanoclusters

“…Significantly, in combination with erbium as a dopant, the Si-ncs have been found to serve as effective sensitizers, producing enhanced Er photoluminescence ͑PL͒ and electroluminescence [2][3][4] at the important telecommunications wavelengths around 1.55 m. As a result, this material has been suggested as a promising candidate for silicon-based lasers or optical amplifiers. 5 The sensitization process in this material remains relatively poorly understood, although it is generally agreed that a high degree of control over the size distribution, density and crystallinity of Si-ncs is required to fully optimize the material parameters.…”

Sensitization of Er luminescence by Si nanoclusters

“…Moreover, electrical excitation can also be achieved and efficient electroluminescent devices have recently been demonstrated. 11 In the current study, we investigate in detail the sequential excitation mechanism of Er 3+ ions in SiO 2 : Si-nc: Er. In particular, we show that under certain excitation conditions, the emission is limited by the concentration of Si-nc coupled to Er 3+ ions.…”