Interaction between CdS nanocrystals and PVP leading to co-operative growth of CdS-PVP nanocomposites: A Raman and AFM mapping study

•Same selected areas of CdS-PVP nanocomposites are studied by Raman, PL, AFM mapping.•CdS nanocrystals (NCs) are embedded either in thin-film or spheres of PVP.•Correlation between monodispersive NCs and morphology of nanocomposite is developed.•Interaction between CdS NCs and PVP depends on density of NCs.•Interaction leads to the co-operative growth mechanism of CdS-PVP nanocomposites.

CdS-PVP nanocomposites grown with various concentrations of Cd+/S− and PVP are studied using Raman and atomic force microscopy mapping on same selected areas. The study shows that CdS nanocrystals are embedded in either a thin-film or spheres of PVP, formation of which depends on relative ratio of Cd+/S− concentration (density of nanocrystals) to PVP. Collapse of PVP from planer matrix to the sphere morphology is correlated with high density of CdS nanocrystals and the attractive interaction between CdS nanocrystals and PVP polymer leading to a co-operative growth mechanism. The understanding developed can be used to control the growth of CdS-PVP nanocomposites with desired properties for optoelectronic device applications.