Effect of ZnO seed layer on the growth of CdS nanostructures for optoelectronic applications

In this study, the influence of the ZnO seed layer on the growth of CdS nanostructures using chemical bath deposition method was studied. Applied ZnO seed layer led to change the surface morphology of deposited CdS on glass substrate from particle shape to nanosheet. The results indicated an improvement in the homogeneity and uniformity of the grown CdS nanostructures on ZnO seed layer, which can be due to the low lattice mismatch between ZnO and CdS structures. This change led to variation in crystal structure from cubic to hexagonal. The UV-Vis spectroscopy illustrated the higher absorption coefficient for CdS nanosheet related to CdS particle shape due to the high specific surface area. The calculated band gap of this sample by Tuac plot showed the value of 2.62 eV, which was increased compared to the cadmium sulfide with the bulk structure, which is due to the improved crystal quality of nanosheets. The results showed improved optoelectrical properties of optical detectors based on cadmium sulfide nanoparticles compared to the other samples.