The role of Er3+-Er3+ separation on the luminescence of Er-doped Al2O3 films prepared by pulsed laser deposition

Erbium-doped Al2O3 films have been deposited in a single step process by pu lsed laser deposition using independent ablation of Al2O3 and Er targets. T his procedure allows to control the Er3+ ions in-depth distribution. The ch aracteristic Er3+ photoluminescence at 1.54 mu m shows lifetime values whic h increase from 6.0 to 7.1 ms when the Er3+-Er3+ in-depth separation is inc reased from 3 to 9 nm. These results are discussed in terms of the ion-ion interaction and clustering for separations shorter than 6 nm. (C) 1999 Amer ican Institute of Physics. [S0003-6951(99)04952-9].