Comparative studies on the laser-induced damage of TiO2 films with different additives and thickness

Abstract

TiO2 films of different thickness were prepared with the additives of acetylacetone (ACAC) and diethanolamine (DEA), respectively. The results showed that not only the additives but also the film thickness affected the optical properties, surface roughness, absorption and laser-induced damage threshold (LIDT) of TiO2 films. The LIDT of the film with DEA was higher than that with ACAC, which was attributed to the lower defect density. With the film thickness increase, the significant decrease in LIDT of the film with ACAC was mainly due to the reduced band gap. It indicated that the amount of ACAC or the film thickness should be reduced as much as possible for preparing high LIDT TiO2 films. After laser damage, the films with ACAC showed cracks, whereas the films with DEA showed spalling. The difference between the damage morphologies was discussed in details.