Linear and nonlinear optical properties of Manganese bis-(8- hydroxyquinoline) thin films for optoelectronic devices: experimental and computational studies

•Thin film of Manganese bis-(8-hydroxyquinoline) (Mnq2) Deposited by the Physical Vapor Deposition technique.•Homogeneous morphology obtained by AFM images.•Thermal photoluminescence emission in the visible range.•The third harmonic generation (THG) response shows good nonlinear optical properties.•Density Functional Theory (DFT) calculations of HOMO, LUMO energy levels and HOMO-LUMO energy gap of Mnq2 evaluated by UPBEPBE/def2tzvp level of theory. Linear and nonlinear optical properties of Manganese bis-(8-hydroxyquinoline) (Mnq2) were investigated in this work as thin film. The thin film of Mnq2 were deposited by Physical Vapor Deposition (PVD) technique in a high vacuum under the pressure 2 × 10-5 Tr. The morphology of the surface of the deposited Mnq2 thin film was analyzed by Atomic Force Microscopy (AFM) in non-contact mode. The AFM image shows an homogenous and a good quality of thin film. Optical parameters such as the energy gap (2.8 eV) were determined by transmittance measurement in the spectral range of 300–1100 nm. A dependence of luminescence at low temperature from 10K to 300K is observed, showing a decrease of luminescence when the temperature increases. Third order nonlinear optical (ONL) response of Mnq2 was measured using the third harmonic generation (THG) technique. Third ONL susceptibility was calculated based on the theoretical model of Kubodera and Kobayashi. The theoretical studies of the absorption spectrum, HOMO, LUMO energy levels and HOMO-LUMO energy gap of Mnq2 have been evaluated by using density functional theory calculations (DFT) using UPBE0/def2-TZVP level of theory. The calculated theoretical values of Mnq2 were found to be in good agreement with the experimental findings. [Display omitted]