Growth and Characterization of Seed-Assisted, EDTA-Treated, Chemical Bath-Deposited CdS

A simple low-cost method to enhance the electrical properties including open-circuit voltage ( V OC ), flat-band potential ( V fb ) and short-circuit current ( I SC ) in the photoelectrochemical (PEC) cell of cadmium sulfide (CdS) thin films is presented. The PEC cell properties were determined using the configuration Pt/0.1 M Na 2 S 2 O 3 /CdS. Three different sets of CdS thin films were grown: (a) chemical bath-deposited CdS (CBD-CdS), (b) electrodeposited seed-assisted CBD-CdS (ED/CBD-CdS) and (c) ED/CBD-CdS deposited under the presence of ethylenediaminetetraacetic acid (EDTA) in a reaction solution of CBD (ED/(CBD+EDTA)-CdS). The FE-SEM images suggested the formation of clusters with spherical shape in the presence of a seed layer. All the samples grown with seed layers demonstrated improved I SC and V OC values in the PEC cell compared to the CBD-CdS films due to better contact between the substrate and CBD-CdS. Furthermore, the carrier concentration ( N D ) and V fb were also found to improve due to the introduction of the seed layer. In the case of ED/(CBD+EDTA)-CdS, the cluster size was found to be smaller, giving rise to a larger effective surface area. The improved effective surface area, interparticle connections and adhesion of CdS to the FTO substrate resulted in superior electrical properties of ED/(CBD+EDTA)-CdS compared to ED/CBD-CdS and CBD-CdS films. Graphical Abstract