Third-order nonlinear optical properties of nanostructured V(2-x)ZnxO5 thin films for optoelectronic device applications

In this article, we present for the first time the influence of Zn on the surface morphology, linear, and third-order nonlinear optical (TONLO) properties of nanostructured vanadium pentoxide (V 2 O 5 ) thin films fabricated via spray pyrolysis (SP) on heated glass substrates at 350 °C with various Zn-doping quantities. Powder X-ray diffraction (P-XRD) studies confirm the polycrystalline nature and orthorhombic crystal structure of the fabricated films. The optical energy band-gap (E g ) of the film's ranges from 3.33 eV to 3.65 eV as the doping concentration increases. The films exhibit reverse saturable absorption (RSA) with a nonlinear absorption coefficient (β) varying from 4.68 x10 −4 to 9.92 x10 −4 (cmW −1 ). The observed negative nonlinear refractive index (n 2 ) indicates the occurrence of a self-defocusing effect, which enhances from 1.37 x10 −8 to 2.40 x10 −8 (cm 2 W −1 ). The calculated TONLO susceptibility (χ (3) ) values also improve from 0.79 x10 −6 to 1.38 x10 −6 (e.s.u). Consequently, we demonstrate the potential use of V 2(1-x) Zn x O 5 thin films as optical limiters for optoelectronic sensors.