An intra-Nd3+ visible to infrared conversion process in hybrid xerogels

The luminescence spectra of a series of Nd3+ -based hybrid xerogels were re ported. The organic/inorganic matrix, classed as di-ureasils, is a siliceou s network to which short polyether-based chains are grafted by means of ure a bridges. The luminescent centers were incorporated as neodymium triflate. These multi-wavelength phosphors present a broad green-blue emission band associated with the hybrid backbone and a series of infrared emissions whic h were assigned to the F-4(3/2)--> I-4(9/2-13/2) intra-4f(3) lines. The vis ible emission spectra provides strong evidence for the existence of an unus ually intra-Nd3+ conversion process of visible light in infrared luminescen ce. (C) 2000 Elsevier Science Ltd. All rights reserved.