Environment of Erbium ina−Si:Handa−SiOx

Abstract

The chemical environment of Er in a-Si:H and a-SiO x :H was determined by extended x-ray absorption fine structure. Only one family of Er sites is found, coordinated on average with two to three O atoms (compared to six in Er 2 O 3 ). We devised a new model for the incorporation of Er in a-Si:H and a-SiO x :H. According to the model, Er is incorporated in the form of ͓ErO d ͔ 1322d complexes, with d # 3. The minimum configuration energy is achieved for d 3 when the valence requirements of Er are fulfilled. The complexes are low symmetry environments that allow the Er 31 luminescent transition at 1.54 mm and make Er an acceptor in a-Si:H whereas it is donor in crystalline silicon.[S0031-9007(98)

Formation of erbium–oxygen nanoclusters in erbium‐doped oxidized amorphous silicon

“…where the constant H = 0.1, adjusted to fit the experimental data, takes account of the competition between the formation of small erbium-oxygen complexes with three oxygen atoms per one erbium [6] and large complexes. The results of calculations are compared with the experimental data in Figs. 1b, c.…”

Self-assembling of supramolecular erbium–oxygen clusters in magnetron plasma, and the optimization of erbium luminescence in a-SiOx:H〈Er,O〉 films

“…In the first region the concentration of erbium will be determined by concentration of erbium clusters with 2-3 oxygen atoms per one erbium (cf. [2,3,10]) and hardly changes until we approach the threshold of large clusters formation ($5 at.%). There two processes of cluster formation compete, the larger clusters have significantly higher probability to arise.…”

“…As shown previously in [1][2][3][4][5][6], the intensity of the erbium (Er 3+ ) photoluminescence I Er PL in a-SiO x :HhEr, Oi films is controlled mainly by the coordination of erbium ions by oxygen, which breaks the symmetry of the erbium site and makes partially allowed the f-f transition in the electronic shell of an erbium ion. Therefore, two main parameters in the technology of fabrication of a-SiO x :HhEr, Oi films by the magnetron-assisted silane deposition (MASD) method are the concentration of oxygen C O 2 in the mixture of gases SiH 4 + Ar forming the magnetron plasma and the area of sputtered metallic erbium target S Er .…”

Temperature independent Er3+ photoluminescence lifetime in a-Si:H<Er> and a-SiOx:H<Er>

“…One possibility is the occurrence of different Er environments in a-Si:H<Er> and aSiO x :H<Er>. Indeed, in our co-sputtered material, Er tends to occupy mainly two families of lattice sites, coordinated to two or three oxygen atoms [12]. The 4 I 13/2 → 4 I 15/2 transition is electric dipole forbidden in the free ion.…”