Acta Metallurgica Sinica (English Letters) ›› 2015, Vol. 28 ›› Issue (5): 559-566.DOI: 10.1007/s40195-015-0232-x

• Orginal Article • Previous Articles     Next Articles

60Co Gamma Irradiation and Annealing Effects on Transport Properties of Antimony Telluride Platelets Grown by Physical Vapor Deposition

Thankamma George, A. G. Kunjomana()   

  1. Crystal Research Centre, Department of Physics, Christ University, Bangalore, 560 029, India
  • Received:2014-08-11 Revised:2014-10-15 Online:2015-02-15 Published:2015-07-23

Abstract:

Physical vapor deposition method was employed to deposit antimony telluride (Sb2Te3) crystals in a dual-zone furnace. The microstructure, surface topography and composition of samples were characterized using X-ray diffraction, atomic force and scanning electron microscopy. Seebeck coefficient (S⊥c), electrical conductivity (σ⊥c) as well as power factor (PF) were enhanced for pure Sb2Te3 samples upon annealing, and the samples annealed at 473 K exhibited the highest PF of 3.16 × 10-3 W m-1K-2 with an enhancement of 22% in the figure of merit (Z). When the delivered dose of 60Co gamma radiation was increased from 0 to 30 kGy in the stoichiometric crystals, σ⊥c decreased due to the decrease in mobility. As a result of the increase in S, PF and Z improved by 12.11 and 13.7%, respectively, in the 30 kGy gamma-irradiated crystals. Both RH (B||c) and S⊥c were positive, suggesting that the prepared Sb2Te3 crystals retained the p-type semiconductivity after these treatments.

Key words: Antimony telluride, Physical vapor deposition, Irradiation, Annealing, Conductivity, Seebeck coefficient