Photoelectronic properties of nanocrystalline CdSethin films prepared by chemical bath deposition (CBD) technique at room temperature are studied taking its molar concentration as a function. Structural analysis of the deposited thin films shows that change of molarity brings a variation in the crystalline sizes of the thin films. Such thin films show suitable photoelectronic properties for the construction of different optoelectronic devices. The photocurrents are observed to be significantly defect controlled in the visible range of wavelengths. The transport mechanism for the thin films is generally a doubly activated process and the photocurrent decay characteristics curves are found to exhibit 2 different decay times which actually correspond to 2 distinct trap levels. HIGHLIGHTS The photoelectronic properties of nanocrystalline CdSe thin films deposited by CBD method are studied From the XRD of the films diffraction peaks may be indexed to diffraction basically from the (111) plane of zincblende structure The optical band gap may be varied with the molarity of the solution used for deposition Photoelectronic properties are dependent of the intensity of different monochromatic illuminations Photocurrents for the films are basically controlled by the grain boundary defects Growth and decay of photocurrent are effectively governed by different kind of traps GRAPHICAL ABSTRACT