Nanomechanical and wettability properties of Bi2Te3 thin films: Effects of post-annealing

Abstract

In this study, Bi2Te3 thin films were deposited on SiO2/Si(100) substrates by pulsed laser deposition (PLD) at 250 degrees C. The films were then annealed in-situ in the deposition chamber at various annealing temperatures (T-a) ranging from 200 to 300 degrees C. The microstructural, morphological, and nanomechanical properties of the Bi2Te3 thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy, and nanoindentation techniques, respectively. The XRD results indicated that all the Bi2Te3 thin films have high crystalline quality with predominant (0015) texture. Nano-indentation measurements performed with a Berkovich nanoindenter operating under the continuous contact stiffness measurement mode revealed that both the hardness and Young's modulus of the Bi2Te3 films decreased with increasing Ta. In addition, the water contact angle measurements were carried out to delineate the effects of annealing on the changes in the surface energy and wettability of the films. Published by AIP Publishing.