Structural and chemical properties of highly oriented cadmium sulfide (CdS) cauliflower films

►CdS is an important material with a potential for a wide range of scientific and technological applications. A wide and direct band gap (∼2.42 eV) coupled with n-type conductivity makes CdS suitable for application in large area optoelectronic devices such as such as solid state lasers and detectors, window layer in hetero-junction solar cells, field-effect transistors, and photoconductors. ► Significant research efforts were directed involving higher temperatures, chemical treatments, intense pulsed-lasers to grow the single phase, oriented CdS films. In this communication, we demonstrate the room-temperature growth of high-quality H-phase CdS thin films with a very high degree of orientation along c-axis. The present work has been performed on CdS films deposited using RF magnetron sputtering, which offers the advantage in simplicity of the process, cost effectiveness, industrial scalability. Interestingly, we found that the high-structural and chemical quality H-CdS layers can be stabilized by carefully controlling the sputtering-power. The results and their implications for technology are presented and discussed in this Letter.