Tuning the structural, morphological, and optical properties of zinc (8-hydroxyquinoline) thin films by laser-irradiation for optoelectronic applications

Abstract

This research represents a deep study of the effect of laser irradiation on the structure, morphological, and linear/nonlinear optical properties of Znq2 thin films prepared by the thermal evaporating technique. After deposition, films were irradiated by continuous wave (CW) diode laser at different exposure times (0.5 h, 1.0 h,1.5 h, and 2.0 h). The analysis of the X-ray diffraction (XRD) patterns revealed the polycrystalline nature of the irradiated thin films at 1.0 h and 1.5 h. Meanwhile, the amorphous nature dominated the structure after irradiation of thin films at 0.5 and 2.0 h. The molecular structure of Znq2 showed a high degree of stability at exposure time up to 1.5 h. The morphology of the Znq2 thin films demonstrated the maximal grain size and lowest roughness after 1.0 h irradiation, while, at 1.5 and 2.0 h, the roughness increased. Measuring the transmittance and reflectance of irradiated thin films revealed how the laser exposure time affects linear and nonlinear optical parameters. The optical dispersion behavior is discussed in the light of the single oscillator model. The dielectric function and optical conductivity at different irradiation durations have been estimated and explained. The 1.0 h irradiated thin film has the lowest absorbance, Urbach tail energy, SELF, and VELF. In addition, the irradiated Znq2 thin film at 1.0 h recorded the highest value of optical mobility. Interestingly, the CW laser irradiation process induced tunable structural, morphological, and linear/nonlinear optical properties of Znq2 thin films, which can provide unique advantages and capabilities in industrially scalable schemes.