Cairo University

MTPR Journal

 

SYNTHESIS OF RARE-EARTH DOPED AND UNDOPED GaN NANO-CRYSTALLITES

& doi: https://doi.org/10.1142/9789814504898_0014
LOTFIA EL NADI, SAMAH AHMED, M. AWAAD, MAGDY OMAR and YEHIA BADR
National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza, Egypt

Physics Department, Laser Physics Lab. Faculty of Science, Cairo University, Giza, Egypt


Vol./Issue: 13 , id: 355

Semiconductor nanostructures doped with rare earth ions is a possible way to overcome the limitation of low luminescence efficiency of rare earth ions, providing that the strong confinement of carriers in dots will enhance their recombination in the vicinity of RE ions. Undoped and Eu3+-doped GaN crystallites have been synthesized by the co-precipitation method followed by nitridation reaction at 1100 °C for 2 h, under a continuous flow of NH3 gas. X-ray diffraction patterns (XRD) revealed that the synthesized undoped and Eu3+-doped GaN crystallites are of a single-phase wurtzite structure. The morphology of the samples was examined by field emission scanning electron microscope (FE-SEM) and high resolution transmission electron microscope (HR-TEM), and it was shown that the micron-sized particles are composed of agglomerated nano-crystallites. Under the above band gap excitation, all samples exhibited room-temperature photoluminescence with the characteristic GaN band-edge emission peak centered at 363 nm (∼3.4 eV, FWHM ∼ 10 nm) as well as broad defect-related emission peak centered at about 405 nm. The Eu-doped GaN sample, under below bandgap excitation, exhibited red emission peaks centered at 593 nm and 616 nm corresponding to the 5D0 → 7F1 and 5D0 → 7F2 transitions, respectively, within the 4f shell of Eu3+ ions.