A Contribution of Thermoelectric Properties of the Quaternary Chalcogenide Compound Tl2GaInSe4 Crystal
R.H. Al Orainy
Physics Department, Sciences of Faculty for Girls, King Abdulaziz University, Jeddah, Saudi Arabia
Received: February 14, 2013; In final form: April 12, 2013
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Thermoelectric transport measurements were made on single crystal samples of Tl2GaInSe4. The crystal was prepared by a special design based on the Bridgman technique. Measurements of thermoelectric power were carried out in a special high vacuum-tight calorimeter when the direction of temperature gradient is perpendicular to the cleavage plane. The measurements covered a temperature range extending from 300 to 725 K. The results indicate P-type conductivity for our investigated samples. At room temperature the value of thermoelectric power was 735 μV/deg. The electron to hole mobility ratio was found to be 1.35. The effective mass of holes at room temperature was evaluated as 4.635×10-29 kg, while for electron was equal to 8.468×10-31 kg. The relaxation time of majority and minority carriers was estimated as τp=2.968×10-10 s and τn=7.326×10-12 s, respectively. Also, the diffusion coefficient of holes and electrons at room temperature was calculated and found to be 265.132 cm2/s and 358.139 cm2/s, respectively. The diffusion length of holes and electrons are found to be Lp=2.805×10-4 cm and Ln=5.122×10-5 cm. In addition to these pronounced parameters, the efficiency of thermoelectric element (figure of merit) was evaluated which leads to better applications in many fields.

DOI: 10.12693/APhysPolA.124.728
PACS numbers: 74.25.fc