P-type electrical transport properties and excellent Hall mobility of GaSb single crystal grown by Ga flux

Semiconductor materials, especial the Gallium antimonide (GaSb), have many unique properties and potential application, which attracted significant research interest. However, GaSb single crystal always shows a lower mobility due to the intrinsic defects, which greatly limits its application in electronic and optoelectronic devices. Here, GaSb single crystal has been grown by the Ga as the self-flux method. The properties of temperature dependent structure and surface morphology have been systematically investigated. The temperature dependent vibration modes of longitudinal optical and transverse optical were studied with Raman spectra. The thermal conductivity and thermoelectric measurements were on GaSb single crystal. The thermoelectric results revealed the Seebeck coefficient (S) is 552 μV/K at 300 K, which is conducive to thermoelectric property. The electrical resistivity and Hall coefficient display semiconducting behaviors with energy gaps of 34.5 and 29.2 meV, respectively. In particular, the Hall mobility reaches 1066 cm2/V·s at 300 K, which is superior than most of the GaSb single crystals grown by other methods. The mechanism of high Hall mobility related to the native defect concentration and dislocation density on the GaSb single crystal was discussed.