Interaction of oxygen with (Er + Si): formation of erbium pyrosilicate Er2Si2O7

Local structure analysis of an optically active center in Er-doped ZnO thin filmThe local structure of erbium-doped silicon produced by the laser ablation technique is investigated by Er L III -edge x-ray absorption fine structure analysis. The combined analysis of extended x-ray absorption fine structure analysis and an x-ray absorption near-edge structure simulation based on multiple-scattering theory reveals the most probable atomic coordination of the optically active center; Er bonded with six oxygen atoms has a C 4v symmetry. The optical activation process of this system is also discussed. The Si target with 10 wt% Er 2 O 3 has two kinds of local structures, C-rare-earth Er 2 O 3 grain and another Er phase incorporated in Si. The laser ablation homogenizes these phases, and deposits a new single-phase structure of the octahedron ͑O h point group͒ on the substrates. In this phase, the optical transition probability is low due to the forbidden 4 f transition of Er in the crystal field originating from the higher-order symmetry of O. After annealing, degradation of the symmetry from O h to C 4v results in a crystal field suitable for inducing sufficient radiation transition.

Section: Experiments and Local Structure Analysismentioning

confidence: 99%

The optically active center and its activation process in Er-doped Si thin film produced by laser ablation

Ishii

Ishikawa

Ueki

et al. 1999

“…8,9 Although the photoelectric properties of pure RE metals and certain specific RE-containing compounds have received substantial attention, 10 that is not true for RE-doped semiconductors, excepting compositional analyses, in particular erbium in silicon. 11 Photoelectron spectroscopic studies of RE-doped semiconductors could provide further insight into the electronic/structural proper-ties of RE 3ϩ ions in a specific semiconductor matrix, and lead to substantial improvements in the processing and design of optoelectronic devices.…”

Section: Introductionmentioning

confidence: 99%

X-ray photoelectron spectroscopic study of rare-earth-doped amorphous silicon–nitrogen films

Zanatta¹,

Ribeiro

Alvarez

2003

, and Lu͒ have been prepared by cosputtering. The films were investigated in detail by x-ray photoelectron spectroscopy employing 1486.6 eV photons. Additional information was also achieved by optical techniques and ion beam analyses. As a result of the deposition method and conditions, the films present similar contents of Si and N, and rare-earth concentrations below 1.0 at. %. In spite of this relatively low concentration, and taking advantage of the high photoionization cross section of the rare-earth elements at 1486.6 eV, the signal of several different core-levels and Auger transitions could be detected and analyzed. The electronic states at the top of the valence band of the RE-doped a-SiN films were also investigated with 1486.6 eV photons. Compared to the spectroscopic data of pure metals, the RE-related core levels of the present a-SiN films exhibit an energy shift typically in the 0.8-2.5 eV range, which is attributed to the presence of nitrogen atoms. According to the experimental data, most of the RE ions remain in the 3ϩ state. The only clear exception occurs in the Yb-doped a-SiN film, where a large fraction of Yb 2ϩ coexisting with Yb 3ϩ ions is evident.

“…It is believed that Er 2 Si 2 O 7 phase appeared at the interface between BST:Er thin films and silicon substrate during the process of the high temperature sintering. 26 In addition, the minor line at 31°that has been ascribed to Er 2 Ti 2 O 7 phase was observed as well. 27,28 We show the XRD patterns of BST films doped with various Er concentrations sintered at 700°C in Fig.…”

Section: Resultsmentioning

confidence: 74%

Dependence of luminescence efficiency on dopant concentration and sintering temperature in the erbium-doped Ba0.7Sr0.3TiO3 thin films

Kuo

Chen

Tseng

et al. 2002

Articles you may be interested inPhase separation and direct magnetocaloric effect in La 0.5 Ca 0.5 MnO 3 manganite Modeling the crystal-field splitting of energy levels of Er 3 + ( 4 f 11 ) in charge-compensated sites of K Pb 2 Cl 5We found the dependence of luminescence efficiency on Er 3ϩ concentration and sintering temperature in the Er-doped Ba 0.7 Sr 0.3 TiO 3 ͑BST͒ thin films is governed by crystallinity and ion-ion interaction. X-ray diffraction and Raman studies of the sol-gel prepared samples show that the BST polycrystalline phase occurred when the sintering temperature reaches 700°C, whereas, it becomes worse for temperature above 700°C resulting from phase separation and the Er 3ϩ concentration exceeding 3 mol % due to charge compensation mechanism. The observed green emission reaches maximum at sintering temperature 700°C and 3 mol % Er 3ϩ ions concentration. We also showed the Er dopant does not affect the dielectric property of BST thin films in C-V measurement and the Ba 0.7 Sr 0.3 TiO 3 films doped with Er 3ϩ ions may have potential use for electroluminescence devices.