Effect of growth temperature on the material properties of PLD-grown Bi2Te3 and Sb2Te3

Abstract

Bismuth Telluride (Bi₂Te₃) and Antimony Telluride (Sb₂Te₃) are the preferable materials for building thermoelectric devices. Pulsed Laser Deposition (PLD) is one of the techniques used to grow these materials. To study the effect of temperature growth on the properties of the materials, thin films were PLD-deposited on n-type Silicon substrate in Argon (Ar) atmosphere. Substrate temperatures changed from 25 °C to 450 °C. The surface morphology of the films was studied using Atomic Force Microscopy (AFM) and their crystal properties were studied using X-ray Diffraction (XRD) analysis. The effect of the growth temperature on the material properties was investigated. AFM scans show how temperature affects the surface morphology. XRD results show that all the films are polycrystalline, and at higher temperatures both films have specific preferred orientations, namely along the (006) and (00 15) planes. Both Bi₂Te₃ and Sb₂Te₃ were found to have hexagonal crystal lattice structure with lattice constants a = 4.396 Å and c = 30.486 Å for Bi₂Te₃ and a = 5.075 Å and c = 30.451 Å for Sb₂Te₃. The grain sizes of all the films were calculated using Scherrer formula and plotted as a function of temperature for both the materials.