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Enhancement of thermoelectric efficiency in vapor deposited Sb 2 Te 3 and Sb 1.8 In 0.2 Te 3 crystals
Author(s) -
Thankamma G.,
Kunjomana A. G.
Publication year - 2014
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201300318
Subject(s) - thermoelectric effect , seebeck coefficient , materials science , analytical chemistry (journal) , doping , figure of merit , indium , chemical vapor deposition , scanning electron microscope , crystal growth , thermoelectric materials , thermal conductivity , crystal (programming language) , single crystal , mineralogy , crystallography , optoelectronics , chemistry , physics , computer science , programming language , chromatography , composite material , thermodynamics
Pure and indium doped antimony telluride (Sb 2 Te 3 ) crystals find applications in high performance room temperature thermoelectric devices. Owing to the meagre physical properties exhibited on the cleavage faces of melt grown samples, an attempt was made to explore the thermoelectric parameters of p‐type crystals grown by the physical vapor deposition (PVD) method. The crystal structure of the grown platelets (9 mm× 8 mm× 2 mm) was identified as rhombohedral by x‐ray powder diffraction method. The energy dispersive analysis confirmed the elemental composition of the crystals. The electron microscopic and scanning probe image studies revealed that the crystals were grown by layer growth mechanism with low surface roughness. At room temperature (300 K), the values of Seebeck coefficient S (⊥ c) and power factor were observed to be higher for Sb 1.8 In 0.2 Te 3 crystals (155 μVK −1 , 2.669 × 10 −3 W/mK 2 ) than those of pure ones. Upon doping, the thermal conductivity κ (⊥ c) was decreased by 37.14% and thus thermoelectric efficiency was improved. The increased figure of merit, Z = 1.23 × 10 −3 K −1 for vapour grown Sb 1.8 In 0.2 Te 3 platelets indicates that it could be used as a potential thermoelectric candidate.