Thermoelectric properties of p-type (Bi2Te3)x(Sb2Te3)1−x crystals prepared via zone melting

Abstract In the present study, p-type (Bi 2 Te 3 ) x (Sb 2 Te 3 ) 1− x crystals with various chemical compositions ( x = 0 , 0.05, 0.10, 0.16, 0.20, 0.24 and 0.26) were fabricated through the zone melting method. Thermoelectric properties, including Seebeck coefficient ( α ), electrical conductivity ( σ ) and thermal conductivity ( κ ), were measured in the temperature range of 300–500 K. The influence of the variations of Bi 2 Te 3 content ( x ) on the thermoelectric properties was studied. The increase of Bi 2 Te 3 content ( x ) caused a decrease in hole concentration and thus a decrease of σ and an increase of α . The maximum figure of merit ( ZT = α 2 σ T / κ ) of 1.14 was obtained at about 350 K for the composition of 24% Bi 2 Te 3 –76% Sb 2 Te 3 with 3 wt% excess Te.

[1]  Jorge O. Sofo,et al.  Stress-induced defects in Sb 2 Te 3 , 2003 .

[2]  J. Navrátil,et al.  Thermoelectric properties of p-type antimony bismuth telluride alloys prepared by cold pressing , 1996 .

[3]  F. D. Rosi,et al.  Improving yield and performance in pseudo-ternary thermoelectric alloys (Bi2Te3)(Sb2Te3)(Sb2Se3) , 1997 .

[4]  T. Oh,et al.  Thermoelectric properties of the p-type Bi2Te3–Sb2Te3–Sb2Se3 alloys fabricated by mechanical alloying and hot pressing , 2000 .

[5]  A. Yamamoto,et al.  Thermoelectric properties of p-type (Bi2Te3)x(Sb2Te3)1−x prepared via bulk mechanical alloying and hot pressing , 2000 .

[6]  V. S. Raghunathan,et al.  Processing and properties of thin films of high critical temperature superconductors , 2003 .

[7]  O. B. Sokolov,et al.  The variation of the equilibrium of chemical reactions in the process of (Bi2Te3)(Sb2Te3)(Sb2Se3) crystal growth , 2002 .

[8]  D. Rowe.  CRC Handbook of Thermoelectrics , 1995 .

[9]  L. Koudelka,et al.  Energy formation of antisite defects in doped Sb2Te3 and Bi2Te3 crystals , 1986 .

[10]  P. Klemens.  Thermal Conduction In Solids , 1976 .

[11]  M. Stordeur,et al.  Antisite defects in Sb2-xBixTe3 mixed crystals , 1988 .

[12]  R. F. Brebrick.  Homogeneity ranges and Te2-pressure along the three-phase curves for Bi2Te3(c) and a 55–58 at.% Te, peritectic phase , 1968 .

[13]  M. Dresselhaus,et al.  Recent developments in thermoelectric materials , 2003 .

[14]  Y. Cho,et al.  The effect of excess tellurium on the thermo electric properties of Bi2Te3-Sb2Te3 solid solutions , 1994 .

[15]  G. Kozhemyakin,et al.  Growth and investigation of thermoelectric properties of Bi–Sb alloy single crystals , 2000 .

[16]  M. Imamuddin,et al.  Thermoelectric properties of p‐type Bi2Te3–Sb2Te3–Sb2Se3 alloys and n‐type Bi2Te3–Bi2Se3 alloys in the temperature range 300 to 600 K , 1972 .