Nanostructuring the Er3+ distribution in PbO–Nb2O5–GeO2 thin film glasses

Abstract

Nanostructured thin film glasses with a controlled concentration and in-depth distribution of Er3+ have been produced by alternate pulsed laser deposition (PLD) from host (PbO-Nb2O5-GeO2) and dopant (Er) targets (in-situ doping). Their photoluminescence (PL) response is compared to that of doped films grown by standard PLD using Er3+-doped glass targets (ex-situ doping), by studying the characteristic Er3+ emission at 1.53 ¿m. PL intensity of in-situ doped films is maximized for in-depth separation between Er-doped layers ¿ 5 nm, whereas their lifetime is always longer in the case of nanostructured films having a separation between Er3+ ions similar to that of ex-situ doped films. These results stem from the different distribution of Er3+ ions in the host glass: isotropic 3D for ex-situ doped films or planar 2D for nanostructured films. Thus, the number of neighbor Er3+ ions is larger in the first case, which favours the increase of nonradiative deexcitation due to concentration quenching. 2014 Elsevier B.V. All rights reserved.