Chemical deposition of CdS films by an ammonia-free process with amino acids as complexing agents

•Highly crystalline CdS films were obtained by an ammonia-free chemical process.•Amino acids were used as complexing agents in the chemical bath deposition method.•The stability of the complexes played an important role in the growth of the films.•Films with different thicknesses and band gap energy values were obtained.

Highly crystalline CdS films were deposited by an ammonia-free chemical bath deposition process which uses amino acids as complexing agents. All films have shown the hexagonal (wurzite) structure with preferential orientation in the plane (002). As consequence of the difference in the stability between the Cd–glycine and Cd–alanine complexes, CdS films with different thicknesses were obtained. The band gap energy values of the resulting films were at the range of 2.43 to 2.52 eV.