Enhancement of optical limiting performance in nanocrystalline La3+ doped ZnO film

Zn1-xLaxO nanofilms were prepared on the glass substrate at 723K using the chemical spray pyrolysis technique. All deposits are hexagonal wurtzite structures with intense plane along the (101) plane. The films doped with 3% La3+ ion showed the least crystalline size with maximum dislocation density. The surface morphology of the deposits changed from fibrous to needles like structure with increased dopant concentration. Both red and blue shifts of absorption edge were noticed as a function of dopant in highly transparent deposited films. A systematic variation of the extinction coefficient and the refractive index was noticed with the incorporation of La3+ in the deposits. Various defects oriented in the films were confirmed by photoluminescence spectra. However, white light emission was found for 4% doped film. Third-order nonlinear optical absorption coefficient (β), susceptibility (χ3) and refractive index (n2) values are 15 × 10−1cm/W, 6.11 × 10−4esu, and −0.34 × 10−5cm2/W, respectively for 3% doped film. It was noticed that Zn0.97La0.03O nanofilm is a more suitable optical limiter application. [Display omitted] •Least crystallinity of 3 at% La3+ deposits with (101) plane.•Morphology changes from fibrous to a needle-like structure as the increase in La3+ doping.•4 at % La3+ doped deposits exhibited a white light emission.•β, χ3, and n2 values are 15 × 10−1 cm/W, 6.11 × 10−4 esu and −0.34 × 10−5 cm/W, respectively for 3% doped film.•3% doped sample suitable for optical limiter applications.