Pressure influence on structural and optical behaviors of ZnTe thin films grown by PLD

摘要

In this work, ZnTe thin films were grown by pulsed laser deposition technique with the aim of study their structural and optical behaviors as function of deposition pressure and consider their potential application in optoelectronic devices. Hence, to obtain the stoichiometric ZnTe phase, the deposition temperature was considered as constant (286 °C) during growth process and deposition pressure was varied, as follow: 1, 20, 50, and 100 mTorr. After that, deposited films were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and UV–Vis spectroscopy techniques. Characterization results reveals that deposited films correspond to stoichiometric, nanostructured, uniform and monophasic deposits of ZnTe with a strong preferential orientation in the (111) plane. It is noteworthy that thickness, grain size and crystal size of the films do not show a linear dependence on the range of deposition pressure. On the other hand, UV–Vis spectroscopy results indicate that band gap values of ZnTe films can be tuned in the range of 2.43–2.56 eV as function of deposition pressure. Lastly, it is consider that ZnTe thin films deposited at 20 mTorr present the best match between structural and optical characteristics for potential applications in development of optoelectronic devices.