Deposition and photoluminescence of sol-gel derived Tb3+: Zn2SiO4 films onSiO2/Si

Tb3+ doped Zn2SiO4 films have been deposited on SiO2 buffered Si wafers by sol-gel method. The structures of these films have been investigated with X -ray diffraction (XRD), atomic force microscopy (AFM), and scanning electro n microscopy (SEM). The results revealed that these films were composed of nanometer-size grains with a Willemite structure and had smooth surfaces. P hotoluminescence measurements of the films showed a strong emission from D- 5(4) to F-7(5) at 544 nm. The blue emission from D-5(3)-F-7(j) was depresse d because of cross-relaxation effect. The decay kinetics of the D-5(4)-F-7( 5) green emission was studied and a best fitting was obtained by a double e xponential function. The lifetime of the excited D-5(4) State is estimated to be 5.2 ms. (C) 2000 Elsevier Science S.A. All rights reserved.