Characterization of laser dye concentrations in ZnO nanostructures for optimization of random laser emission performance

Abstract

Many nanoforms of zinc oxide (ZnO) structures can be synthesized, such as spheres, rods, flowers, disks and walls, as scatter centers in random laser. However, nanoflower and nanowire shapes in this work have received particular interest due to their wide range of applications, including biological, medical cancer cell detection, gas sensors, and biosensors. In this paper, we investigate the optical and morphological properties of two-shaped nanoparticles as scatter centers in the laser active medium on the performance emission of a random laser. Fluorescence and absorption spectra show that 10[Formula: see text][Formula: see text]M for R6G dye and [Formula: see text][Formula: see text]cm[Formula: see text] ZnO NPs are the optimal nanocomposite film concentrations for R6G dye. With excitation energies ranging from 3.44[Formula: see text]mJ to 28.34[Formula: see text]mJ and a repetition rate of 2[Formula: see text]Hz, second-harmonic generation Nd: YAG laser Amplified spontaneous emission (ASE) spectra of the nanocomposite films were observed. The results indicated a minimum bandwidth (Full width at half maximum (FWHM)) of 13[Formula: see text]nm at a threshold energy of 8.65[Formula: see text]mJ for ZnO NW (nanowire) nanocomposite films at [Formula: see text][Formula: see text]cm[Formula: see text] with R6G dye at 10[Formula: see text][Formula: see text]M and Poly(methyl methacrylate) (PMMA). The ZnO NF (nanoflower) nanocomposite film had an FWHM of 11[Formula: see text]nm and a threshold energy of 4.8[Formula: see text]mJ at the same concentrations of R6G dye on PMMA.