Journal of Luminescence 109 (2004) 51–59 Characterization of host-lattice emission and energy transfer in BaMgAl 10 O 17 :Eu 2+ Brandon Howe, Anthony L. Diaz* Department of Chemistry, Central Washington University, 400 E. University Way, Ellensburg, WA 98926, USA Received 2 September 2003; accepted 2 January 2004 Abstract Host-lattice emission, energy transfer and degradation processes are characterized in undoped and Eu-doped BaMgAl 10 O 17 . Undoped BaMgAl 10 O 17 exhibits a broad emission centered at 265nm when excited at wavelengths shorter than 190nm. This emission is assigned to exciton recombination at Ba–O groups in the cation layer of the lattice.TheemissionexhibitsexcellentoverlapwiththeexcitationbandofEu 2+ inthishost,providingameansofhost- to-activator energy transfer in the doped phosphor. The exciton emission is relatively stable to thermal damage, but undergoes a peak shift and significant decrease in intensity after exposure to VUV radiation. Heating of VUV-damaged materials in air leads to some repair of the spectral properties. r 2004 Elsevier B.V. All rights reserved. PACS: 78.20.e; 78.55.m; 78.55.Hx Keywords: BaMgAl 10 O 17 ; Eu 2+ ; BAM; Energy transfer 1. Introduction The VUV optical properties of the plasma display blue phosphor BaMgAl 10 O 17 :Eu 2+ (BAM) have been extensively studied in recent years. This phosphor undergoes deterioration of color quality and efficiency both during panel preparation (thermal damage) and during panel operation (radiation damage) [1–4]. Although the mechanismsbehindthesedamageprocessesarestill notwellunderstood,thermaldamageinairappears to be the result of oxidation of Eu 2+ to Eu 3+ . VUV damage may result from a radiation-induced changeintheoxidationstateofEu,frommigration of ions in the Ba–O plane of the host, or from the formation of some other electronic defects. Many methods have been proposed for improving the stability of BAM, ranging from modest composi- tional variations [5–7] to the introduction of trivalent ions into the host lattice [8,9]. However, none of these approaches has led to dramatic improvements in the stability of the phosphor, and many questions remain about the fundamental nature of these degradation phenomena. BAM has the hexaaluminate structure, and crystallizes in the P6 3 /mmc space group. The structure consists of MgAl 10 O 16 spinel-type blocks with intervening Ba–O layers (‘‘cation layers’’). The ARTICLE IN PRESS *Corresponding author. Tel.: 509-963-2818; fax: 509-963- 1050. E-mail address: diaza@cwu.edu (A.L. Diaz). 0022-2313/$-see front matter r 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jlumin.2004.01.019