Synthesis and characterizations of CdS nanorods by SILAR method: effect of film thickness

In this investigation, we have successfully synthesized CdS nanorods by simple and inexpensive successive ionic layer adsorption and reaction (SILAR) method. The effect of film thickness on the physico-chemical properties such as structural, morphological, wettability, optical, and electrical properties of CdS nanorods has been investigated. The XRD pattern revealed that CdS films are polycrystalline with hexagonal crystal structure. SEM and TEM images showed that CdS film surface are composed of spherical grains along with some spongy cluster and an increase in film thickness up to 1.23 μm causes the formation of matured nanorods having diameter 150–200 nm. The increases in water contact angle form 105° to 130° have been observed as film thickness increases from 0.13 to 1.23 μm indicating hydrophobic nature. The optical band gap was found to be increased from 2.02 to 2.2 eV with increase in film thickness. The films showed the semiconducting behavior with room temperature electrical resistivity in the range of 104–106 Ω cm and have n-type electrical conductivity.