Up-conversion emission processes have been studied in a transparent oxylluoride nano-structured glass-ceramic co-doped with Yb3+ and Tm3+ ions. The decay and rise times, and pump power dependence of the different emission peaks have been analysed. The aim was to achieve a complete picture of the dynamics in this multiphoton excitation system. A method based on balance equations for the involved energy levels has been proposed in order to evaluate the up-conversion and decay rates from these levels. The results are analysed from the point of view of potential application to photovoltaic cells. (C) 2011 Elsevier B.V. All rights reserved.