Influence of annealing on the Er luminescence in Si-rich SiO2 layers coimplanted with Er ions

Abstract

The impact of rapid thermal annealing ͑RTA͒ in producing samples by sequential implantation of Si and Er ions into a 200 nm SiO 2 layer combined with different annealing cycles as well as the corresponding room-temperature visible and infrared photoluminescence ͑PL͒ have been studied. The Er-related PL intensity at 1533 nm for the samples prepared by implanting Si with subsequent annealing, followed by Er implantation, and final annealing ͑type I͒ was found to be stronger than the one produced similarly but without the first annealing step ͑type II͒. In fact, the 1533 nm peak intensity in the optimized RTA processed sample is comparable to the PL yield of the furnace-annealed sample. Moreover, the excitation wavelength ͑405 nm͒ was found to be suitable for exciting the Si= O related point defects in the SiO 2 layer and can provide a PL band with a maximum at ϳ580 nm. While this band was further intensified in the presence of Si nanocrystals ͑Si NCs͒, it became weaker by introducing additional Er 3+ ions with a concomitant rise of the 1533 nm Er PL, confirming the visible range pumping of Er 3+ . The detailed spectral analyses suggest that the 580 nm band is the result of the excitation/deexcitation mechanism in molecule such as states in the Si= O or the Si= O state mediated recombination of carriers in Si NCs according to the model proposed by ͓Wolkin et al., Phys. Rev. Lett. 82, 197 ͑1999͔͒. The samples were further characterized by transmission electron microscopy and Fourier-transform infrared spectroscopy. The time-resolved PL measurements and a modeling by rate equations were also performed to determine and justify the energy migration mechanism from Si NC to the neighboring Er 3+ .

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

“…[4][5][6][7][8] It is then essential to nanoengineer the density and distribution of both Er 3+ ions and Si-based sensitizers within the silica matrix. In this regard, several groups have analyzed the influence of different annealing treatments on the optical performance of SRSO:Er layers [9][10][11][12][13] usually deposited at room temperature ͑RT͒ before being subsequently annealed at different temperatures. Such a process allowed the formation of Si-nc sensitizers and then the observation of Er photoluminescence ͑PL͒ under nonresonant optical excitation.…”

Charge propagation dynamics at trapping centers that induce the luminescence of rare-earth dopants in wide-gap materials

“…Basically, the Sm dopant has optical properties that are similar to those of other rare-earth dopants. [12][13][14][15] In fact, the long lifetime persistence was observed in this system. 16 For the DR and PEDR measurements, an impedance analyzer (Wayne Kerr Electronics Ltd. Model 6440B) in two-terminal mode with a peak-to-peak probing voltage of 50 mV was used.…”

Correlation between the microstructure and electroluminescence properties of Er-doped metal-oxide semiconductor structures

“…2 Owing to low solubility of the RE elements in SiO 2 , 5 a significant fraction of RE ions generally prefer to form clusters during postimplantation annealing. 4 In this letter we demonstrate the evolution of microstructure in Er-doped MOSLEDs as a function of Er concentration, ͓Er͔, and underscore its influence on Er electroluminescence.…”

“…2͒ gives an auxiliary platform, where the REbased electroluminescence ͑EL͒ is controlled by the intrashell transitions in partially filled shells. 3 For instance, the intra-4f shell transition ͑ 4 I 13/2 → 4 I 15/2 ͒ of Er 3+ can emit an infrared ͑IR͒ light at ϳ1.53 m. 4 We must note here that while most of the intraband transitions are optically forbidden for RE ions, no such constraint exists during electrical pumping; hence, several EL signals can be expected during electron injection. The temperature and concentration quenching of RE luminescence remain the major limiting factors to achieve maximum efficiency at room temperature ͑RT͒.…”

“…4 Here, the Er-implanted MOS structures were fabricated by standard local oxidation of silicon ͑LOCOS͒ technology with a 200 nm thick thermally grown SiO 2 layer on n-type Si͑100͒ wafers, where the 250 keV Er ions with fluences in the range of ͑1-5͒ ϫ 10 15 ions/ cm 2 were implanted using a typical target current density of ϳ200 nA/ cm 2 . Initially, the Er concentration was determined to be in between 0.3% and 1.4% at R p ͑ϳ115 nm͒ by the SRIM-2006 calculations, 6 which was later confirmed by Rutherford backscattering spectroscopy measurements.…”