Photoluminescence of Er-doped Si-SiO2 and Al-Si-SiO2 sputtered thin films

Er-doped Si-SiO2 and Al-Si-SiO2 films have been deposited by rf-sputtering being annealed afterwards. Annealing behavior of the Er3+:I-4(13/2)-> I-4(15/2) emission of Er-doped Si-SiO2 yields a maximum intensity for annealing at 700-800 degrees C I-4(13/2)-> I-4(15/2) peak emission for Er-doped Al-Si-SiO2 at 1525 nm is shifted from that for Er-doped Si-SiO2 at 1530 nm and the bandwidth increases from 29 to 42 nm. (I13/2 -> I15/2)-I-4-I-4 emission decays present a fast decaying component related to Er ions coupled to Si nanoparticles, defects, or other ions, and a slow decaying component related to isolated Er ions. Excitation wavelength dependence and excitation power dependence for the I-4(13/2)-> I-4(15/2) emission correspond with energy transfer from Si nanoparticles. Populating of the I-4(11/2) level in Er-doped Si-SiO, involves branching and energy transfer upconversion involving two or more Er ions. Addition of Al reduces the populating of this level to an energy transfer upconversion involving two ions. (c) 2007 Elsevier B.V. All rights reserved.