Growth of GaSb Crystal and Evaluation of Its Thermoelectric Properties Along (111) Plane

In this study, group III-V compound semiconductor gallium antimonide (GaSb) crystal is grown by the vertical Bridgman technique. A (111) twinning is generated in the as-grown crystal due to its polarity behavior as the GaSb crystal has a zinc-blende structure. Hall effect measurements illustrate that the as-grown GaSb crystal has n-type semiconductor behavior among the whole temperature range, and the carrier concentration reaches the highest value of 3.27 x 10(18) cm(3) at 900 K. Thermoelectric behavior of GaSb crystals along the (111) plane is investigated. It shows the lowest electrical conductivity of 53.2 S cm(-1) and the highest Seebeck coefficient of -470.0 mu V K-1 at 700 K. However, the largest power factor of 13.7 mu W cm K-2 takes place at 600 K. For thermal conductivity (k), the k value always decreases with increasing temperature, and the lowest k that occurred at around 900 K is about 7.44 W m(-1) K-1. Finally, a maximum figure of merit of 0.082 is obtained at 700 K.