Effect of doping Zn into Sb2Te3 on the structural and optical properties by thermal Evaporation

Abstract

In this work, a thermal vacuum evaporation-based synthesis of pure (Sb2Te3) and zinc-doped antimony telluride (Sb2Te3: Zn) thin films is investigated. Structural properties of films were examined at 3%, 5% and 7% zinc content and thickness of (100, 200 and 300 nm) and few samples were annealed at 100 °C during the processes, and the formation of a polycrystalline hexagonal structure with enhanced crystallinity following annealing was analyzed by X-ray diffraction. Zinc doping led to lattice contraction and a small shift in diffraction peaks. After annealing, SEM surface analysis showed homogeneous quasi-spherical grains with an increase in size and uniformity. The AFM exhibited decreased roughness after annealing. Though initially increased and subsequently lowered by zinc, optical measurements reflected a good visible absorption with energy gap growth after annealing, With doping and annealing, electrical properties showed an increased conduction and decreased activation energy, confirming p-type behavior. With 5% zinc doping and moderate annealing the structural, optical, and electrical characteristics were optimized, allowing for photovoltaic and thermoelectric applications.