Two-photon absorption induced photoluminescence from ZnS nanowires

In this work, the ZnS nanowires was synthesized on Au-coated Si substrate by a vapor phase transport (VPT) method. The morphology and structure of the as-synthesized ZnS nanowires were studied through scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Under excitation of the femtosecond (fs) pulsed laser at 650 nm, a strong ultraviolet (UV) emission centered at 343 nm was observed. The peak position and the relationship between the emission intensity and the excitation intensity demonstrated that the UV photoluminescence (PL) be induced by the two-photon absorption (2PA) process. The characteristics and the generation process of the above nonlinear optical phenomena were investigated in detail. - Highlights: • The ZnS nanowires was synthesized on Au-coated Si substrate by a VPT method. • The structure of the ZnS nanowires was studied through SEM, TEM and XRD. • A strong UV emission induced by the two-photon absorption process was observed. • The generation process of the nonlinear optical phenomena was investigated.