Spectral analysis of synthesized nanocrystalline aggregates of Er 3 + : Y 2 O 3

• Published in: Journal of applied physics 2007-06, Vol.101 (11), p.113116-113116-6
• Main Authors: Gruber, John B., Sardar, Dhiraj K., Nash, Kelly L., Yow, Raylon M., Gorski, Waldemar, Zhang, Maogen
• Format: Article
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.2739316

The absorption and fluorescence spectra of nanocrystalline aggregates of Y 2 O 3 doped with Er 3 + are reported between 8 K and room temperature. The nanocrystalline particles were synthesized from a homogenous solution of the metal ions and urea at elevated temperatures in order to control the precipitation of the mixed hydroxides by a slow uniform reaction throughout the solution. The morphology of the calcinated materials revealed uniformly spherical aggregates 200 nm or less depending on the ratio of the metal ions in the initial solution. Spectra obtained from these particles were analyzed in detail for the crystal-field splitting of the L J 2 S + 1 multiplet manifolds of Er 3 + ( 4 f 11 ) including the ground-state manifold I 15 ∕ 2 4 , and excited manifolds I 9 ∕ 2 4 , F 9 ∕ 2 4 , S 3 ∕ 2 4 , H 11 ∕ 2 2 , F 7 ∕ 2 4 , F 5 ∕ 2 4 , and F 3 ∕ 2 4 . Fluorescence lifetimes and results from an analysis of the intensities of manifold-to-manifold transitions are also reported. The sharp-line absorption and emission spectra are comparable to spectra reported earlier for Er 3 + : Y 2 O 3 grown as large single crystals by a flame fusion method. The results described in the present study suggest that the simple, inexpensive method of preparation that is reported will lead to further investigation of these nanocrystals for their optical properties, especially in the near infrared region of the spectrum.