54 research outputs found
Green, red and infrared Er-related emission in implanted GaN:Er and GaN:Er,O samples
Er-related luminescence near 1.54 mm ~;805 meV! is observed under below band gap excitation at
4.2 K in GaN:Er and GaN:Er,O implanted samples. The spectrum of the recovered damage samples
is a multiline structure. So far, these lines are the sharpest ones reported for GaN. Well-resolved
green and red luminescences are observed in implanted samples. The dependence of luminescence
on the excitation energy as well as the influence of different nominal fluence and annealing
conditions is discussed. Combining the results obtained from photoluminescence and Rutherford
backscattering spectrometry, different lattice sites for the optical active Er-related centers are
identified
Lattice Dynamics of II-VI materials using adiabatic bond charge model
We extend the adiabatic bond charge model, originally developed for group IV
semiconductors and III-V compounds, to study phonons in more ionic II-VI
compounds with a zincblende structure. Phonon spectra, density of states and
specific heats are calculated for six II-VI compounds and compared with both
experimental data and the results of other models. We show that the 6-parameter
bond charge model gives a good description of the lattice dynamics of these
materials. We also discuss trends in the parameters with respect to the
ionicity and metallicity of these compounds.Comment: 16 pages of RevTex with 3 figures submitted as a uuencode compressed
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