A comprehensive understanding of the chemical vapour deposition of cadmium chalcogenides using Cd[(C₆H₅)₂PSSe]₂ single-source precursor: A density functional theory approach

Background: The phosphinato complexes of group IIB are of great interest for their potential toward technological applications. A gas phase mechanistic investigation of the chemical vapour deposition of cadmium chalcogenides from the decomposition of Cd[(C₆H₅)₂PSSe]₂, as a single source precursor is carried out and reported herein within the framework of density functional theory at the M06/LACVP* level of theory. Results: The results reveal that the activation barriers and the product stabilities on the singlet potential energy surface (PES) favour CdS decomposition pathways, respectively. However, on the doublet PES, the activation barriers favour CdS while the product stabilities favour CdSe decomposition pathways, respectively. Contrary to the previously reported theoretical result for Cd[( ⁱ Pr)₂PSSe]₂, CdSe decomposition pathways were found to be the major pathways on both the singlet and the doublet PESs, respectively. Conclusion: Exploration of the complex gas phase mechanism and a detailed identification of the reaction intermediates enable us to understand and optimise selective growth process that occur in a chemical vapour deposition.