In Situ Low-Temperature Chemical Bath Deposition of CdS Thin Films without Thickness Limitation: Structural and Optical Properties

Abstract

In this work, thin CdS films have been deposited using the chemical bath deposition technique (CBD). Different synthesis parameters, such as number of runs, deposition time, and postannealing temperature, are studied and optimized in order to avoid the supersaturation phenomenon and to achieve a low-temperature growth. CdS thin films, of cubic structure, oriented along the (111) direction with homogenous and smooth surface, have been deposited by using the CBD growth process without any annealing treatment. Based on a set of experimental observations, we show that the solution saturation phenomenon can be avoided if the deposition is performed in several runs at a short deposition time. Throughout the CBD technique, it is then possible not only to overcome any film thickness limitation but also to grow the CdS films in a single technological step at a low temperature and without any postdeposition annealing treatment. CdS films with excellent structural quality and a controllable thickness are obtained when the deposition bath temperature is fixed at 65°C. In addition, deposited films exhibit an optical transmittance ranging from 70 to 95% depending on the synthesis parameters, with band gap energy around 2.42 eV. The process developed in this work might be useful for depositing CdS films on flexible substrates.

New Process for the Formation of Mixed-Valence Platinum Sulfide Thin Films from Bulk CdS Layer: Characterization of Physical and Electrochemical Properties

“…Together, these results indicate the n-type conductivity of the CdS-f layer with a donor concentration of N D = 4.2 × 10 17 cm –3 . These results, along with the XPS measurements shown in Figure b, suggest that the CdS-f films used in the conversion process, which transformed the CdS-f layer into a PtSM layer, exhibited similar properties to the CdS-f films previously demonstrated by M. Ouafi and co-workers in ref .…”

Comprehensive Analysis of CdS Ultrathin Films Modified by the Substrate Position inside the Reactor Container Using the CBD Technique

“…The electric field at the substrate–solution interface (Helmholtz layer) could be important in many cases during the nucleation process. It has been found that this field effect increases as the charge of the cation increases, so the adhesion of Cd + ions on the substrate surface may be more favored than that of Cd­(OH) + ions. ,− …”

Mechanism of Chemical Bath Deposition of CdS Thin Films: Influence of Sulphur Precursor Concentration on Microstructural and Optoelectronic Characterizations

“…This arrangement is capable of enhancing the crystallinity and the cubic phase. Moreover, it is responsible for the formation of the first layer on the substrate surface and controls the path of the reaction [65][66][67]. After specific time, the CdS molecules and [Cd(NH 3 ) 4 ] 2+ intermediate complexes began to collide with each other and molecule-by-molecule mechanism was started at this point to form cluster nuclei.…”