On the mechanism of electroluminescence excitation in Er-doped SiO2 containing silicon nanoclusters

Bipolar pulsed excitation of erbium-doped nanosilicon light emitting diodes

“…The saturation of the 1.54 lm emission may be attributed to both a limited amount of optically active Er ions and to the onset of nonradiative recombination processes. 11,16,23 The presence of the last is evidenced by the decrease of the luminescence decay time shown in Fig. 4, which we will discuss later.…”

“…Electrical charge transport in our Si-NC LEDs is due to electric field-enhanced tunneling of electrons with the involvement of either defects [14][15][16] or confined energy states of Si-NCs. 17,18 Erbium implantation produces deep energy trapping levels which change the transport properties of the Si-NC LED.…”

Electroluminescence from Er and Yb co-doped silicon dioxide layers: The excitation mechanism

“…Due to the low absorption cross section of erbium ions the excitation of the Er 3+ can be significantly enhanced by an energy transfer from sensitizers to the erbium atoms. Besides silicon clusters [3], ytterbium is the most suitable candidate for the luminescence enhancement from erbium because of the overlap between ytterbium infrared emission band and the absorption band of Er 3+ ions. In such a case the resonant energy transfer from the 2 F 5/2 energy level of Yb 3+ to the 4 I 11/2 state of Er 3+ followed by the nonradiative de-excitation to the metastable 4 I 13/2 state takes place [2,[4][5][6][7].…”

Efficient silicon based light emitters

“…It turns out that the Si nanocrystals act as 'sensitizers' for the Er 3C , i.e. they help to provide an efficient energy transfer to the Er 3C ions, thus enabling efficient MOS type LEDs emitting at 1.54 mm [15][16][17][18].…”