Z. Fleischman

Combined Excitation Emission Spectroscopy of Europium ions in GaN and AlGaN films

Site-selective combined excitation emission spectroscopy studies have been performed on Eu-doped GaN and numerous sites have been identified. Relative numbers and broadening of these peaks has been investigated for different growth conditions and for increasing AL content of the Al x Ga 1-x N alloy.

The Site Selectivity of the E-beam Excitation of Eu ion in GaN

GaN is a very promising semiconductor host for rare-earth (RE) based electrically-pumped light emitters. Recently, simulated emission in Eu-doped GaN has been reported under optical excitation, rekindling the hope that an electrically-pumped rare-earth-doped semiconductor laser can be realized. In these laser experiments performed under pulsed UV excitation, it was noted that by changing the resonator length the emission wavelength is shifting suggesting that different types of Eu ions are contributing emphasizing the importance to understand the excitation mechanism for different incorporation sites of the ion. This is the purpose of this work.

A Silicon-based Light Emitter

Although silicon is the leading semiconductor in the microelectronics industry, it is unable to perform as well in the optical area due to its indirect band gap and the lack of a strong electro-optic effect. Among the different approaches developed to overcome the intrinsic low efficiency of silicon as a light emitter, quantum confinement and rare earth doping of silicon (Fujii et al., 1997) have dominated the scientific scenario of silicon-based microphotonics. Especially, direct-current-injection excitation of erbium ions in silicon dioxide structure has showed significant luminescence at 1.54 mum (Castagna et al., 2003), which generated significant renewed interest in the potential of efficient silicon-base light emitters for communications applications

Combined excitation emission spectroscopy of Eu-doped GaN

In this contribution we address the first task by applying to the Eu:GaN material system the site-selective technique of combined excitation emission spectroscopy, in which a large number of emission spectra are recorded and a 2D data set of emission intensities as function of excitation and emission intensity is obtained.