INFLUENCE OF ARGON PRESSURE ON MICROSTRUCTURE AND OPTICAL PROPERTIES OF Zn0.9Se:Co0.1 THIN FILMS PREPARED BY PULSED LASER DEPOSITION

Abstract

Zn[Formula: see text]Se:Co[Formula: see text] thin films were deposited on sapphire (Al2O3) substrates in argon atmosphere at various gas pressures by pulsed laser deposition. Influence of argon pressure on the thickness, surface morphology, crystal structure and optical properties of the thin films were investigated by various diagnosis tools. It was found that these physical properties were correlated to the argon pressure and appeared like a mutation between the pressure of 2[Formula: see text]Pa and 4[Formula: see text]Pa. As the deposition pressure changed from 2[Formula: see text]Pa to 4[Formula: see text]Pa, the collision probability between ablated species and argon molecule was increased, which resulted in the transformation of the deposition type from sputter effect to adsorption effect and the mutation of film thickness and structure. These in turn influence the transmission range and band gap of the films. All of the results suggest that the ambient pressure is a very important factor to the deposition of Zn[Formula: see text]Se:Co[Formula: see text] films by PLD.