Adriana Scarangella; Riccardo Reitano; Francesco Priolo; Maria Miritello
Abstract
The paper reports the potentialities of innovative silicon compatible materials for light emitting devices. In particular thin films of Er doped yttrium oxide have been synthesized by a technique totally compatible with ULSI processes. Through the structural characterization, we will verify the high ...
Read More
The paper reports the potentialities of innovative silicon compatible materials for light emitting devices. In particular thin films of Er doped yttrium oxide have been synthesized by a technique totally compatible with ULSI processes. Through the structural characterization, we will verify the high stability of the film and the good dopant dissolution. Moreover, by the investigation of the optical properties, we will demonstrate that the use of this compound is effective to introduce more than 10 21 Er/cm 3 in optically active state, value that cannot be reached in other Si compatible materials. The influence of Er content on the optical properties will be described in details. Moreover, we will propose the introduction of a proper sensitizer for Er, bismuth, in the same thin film. In particular, we will show that the (Er+Bi) co-doped yttrium oxide is a perfect host to overcome another important drawback of Er doped materials that is its low absorption cross section. The influence of Bi and Er contents on optical properties will be extensively discussed along the paper. Through the optimization of ratio between Bi and Er concentrations, high energy transfer efficiency will be reached with simultaneously a consistent increase of the effective Er cross section. A factor of more than three orders of magnitude have been obtained with respect to the direct excitation of Er.
C. Jayachandraiah; G. Krishnaiah
Abstract
Pure and erbium (1.30, 1.79, 2.83 and 3.53 at. %) doped ZnO nanoparticles are synthesized by wet chemical co-precipitation method. The synthesized samples are characterized by powder X-ray diffraction (XRD), energy-dispersive analysis of X-rays (EDAX), transmission electron microscopy (TEM), Raman spectroscopy, ...
Read More
Pure and erbium (1.30, 1.79, 2.83 and 3.53 at. %) doped ZnO nanoparticles are synthesized by wet chemical co-precipitation method. The synthesized samples are characterized by powder X-ray diffraction (XRD), energy-dispersive analysis of X-rays (EDAX), transmission electron microscopy (TEM), Raman spectroscopy, UV–visible diffusion reflectance spectroscopy (DRS) and LCR Impedance spectroscopy. The XRD measurements confirmed the hexagonal wurtzite structure of all samples and size of the particle is found to be decreased with Er content. TEM images show spherical shape with more agglomeration in Er doped ZnO nanoparticles. Raman spectra confirmed the hexagonal wurtzite structure of pure and Er doped ZnO nanoparticles with E2 (high) mode at 438 cm -1 and presence of other possible defects. UV visible DRS shows decrease in the band gap with increasing Er 3+ in ZnO host. Dielectric constant, dielectric loss factor and ac conductivity properties were decreased with Er dopant in tune with Maxwell -Wagner principle and surface-orientation polarizations.
Wang Zhongjun; Zhu Jing; Wang Zhaojing; Kang Baohua
Abstract
In this paper, the microstructure and creep properties of a cast Mg-3Er-0.2Mn alloy was investigated. The results showed that the cast alloy under both as-cast and solution treated conditions is mainly composed of α-(Mg) matrix and Mg24Er5 phase particles. The value of activation energy Q (240~244KJ/mol), ...
Read More
In this paper, the microstructure and creep properties of a cast Mg-3Er-0.2Mn alloy was investigated. The results showed that the cast alloy under both as-cast and solution treated conditions is mainly composed of α-(Mg) matrix and Mg24Er5 phase particles. The value of activation energy Q (240~244KJ/mol), for creep deformation of the solution treated alloy, was calculated in the temperature range of 190~210 o C, and in the stress range of 50~60 MPa, respectively, which can explain that the creep mode involved cross slip of dislocations from basal to prismatic planes in the hexagonal structure or climb.
)