Efficient energy transfer from Si-nanoclusters to Er ions in silica induced by substrate heating during deposition

Abstract

Articles you may be interested inResonant structures based on amorphous silicon suboxide doped with Er 3 + with silicon nanoclusters for an efficient emission at 1550 nm J. Vac. Sci. Technol. B 27, L38 (2009) This study investigates the influence of the deposition temperature T d on the Si-mediated excitation of Er ions within silicon-rich silicon oxide layers obtained by magnetron cosputtering. For T d exceeding 200°C, an efficient indirect excitation of Er ions is observed for all as-deposited samples. The photoluminescence intensity improves gradually up to a maximum at T d = 600°C before decreasing for higher T d values. The effects of this "growth-induced annealing" are compared to those resulting from the same thermal budget used for the "classical" approach of postdeposition annealing performed after a room temperature deposition. It is demonstrated that the former approach is highly beneficial, not only in terms of saving time but also in the fourfold enhancement of the Er photoluminescence efficiency.

Optical and structural properties of SiO 2 co-doped with Si-nc and Er3+ions

“…The increase of the PL efficiency is due to an enhanced coupling between the Er ions and the Si-ncs sensitizers whose formation is increasingly favored by the annealing up to 900°C. The earlier reported increase of the optically active ions with the thermal budget provided an additional support to our explanation [15]. Moreover, the decrease of the visible emission when Ta is raised from 600 to 900°C, down to ten times for the RT sample, corroborates our suggestions, inasmuch as the coupled Si-ncs are unable to contribute to the visible emission.…”

“…To note, however, that this PL efficiency is systematically higher for the 500°C-deposited sample. This behavior of Er emission against T d was already observed for the emission from asdeposited samples grown at different temperatures [15]. The maximum observed after annealing is around four times higher than that measured for the as-deposited samples.…”

“…Such a process allowed the formation of Si-nc sensitizers and then the observation of Er photoluminescence (PL) under non resonant optical excitation. However, our group has recently observed an Er PL under these indirect excitation conditions on the asdeposited samples at about 500°C [13][14][15]. The Er emission was improved after annealing at about 600°C, and this aspect was also confirmed by another team on similarly sputtered layers [16].…”

Thickness-dependent optimization of Er3+ light emission from silicon-rich silicon oxide thin films

“…However, the x parameter was found to increase from x = 1.555 ± 0.004 for RT-deposited samples to x = 1.616 ± 0.009 for T d = 500°C. This reflects a lowering of Si excess due to the increasing desorption of SiO with T d , as observed in our recent work [12]. For the FTIR approach, which is based on the shift of the TO 3 peak towards that of stoichiometric SiO 2 [13], the detection of Si excess is limited to the Si atoms bonded to O, and does not take into account the agglomerated Si atoms [13].…”

Structural factors impacting carrier transport and electroluminescence from Si nanocluster-sensitized Er ions

“…The composition of the active layer was found to be unchanged when the film thickness was varied; further details of the deposition, as well as structural and compositional investigations, can be found elsewhere [28]. The deposition temperature was maintained at 500°C, corresponding to the optimum luminescent properties determined in a previous study [29]. A thin layer of Indium Tin Oxide (ITO) was then deposited on the whole surface and aluminum contacts were deposited as empty-square shapes to allow the emitted light to be transmitted through the top of the device (Fig.…”