Composition dependent structural, Raman and nonlinear optical properties of PVA capped Zn1-x-yCdxCuyS quantum dots

Composition dependent structural, optical nonlinear and limiting properties of PVA capped Zn1-x-yCdxCuyS quantum dots at different Cu:Zn ratio synthesized by insitu technique is subjected to detailed investigation. Cubic phase of the quantum dots were identified from XRD with particle size in the range 2.5 nm-3.5 nm find excellent correlation with the particle size measured from TEM. With increase in Cu concentration: systematic increment in lattice parameter, red shift in absorption edges and luminescence quenching is observed. Raman scattering reveals good photoactivity evidenced by intensity variation and shifting of LO and TO phonon modes. The intensity dependent third order nonlinearity is studied using Q switched Nd: YAG laser with 532 nm irradiation. Progressive increase in 3 PA coefficient indicated that prepared samples exhibit good nonlinear and optical limiting properties.