Research Article
D. S. Maske, P. S. More, M. D.
Abstract
The VDS technique was used for the crystal growth of InSb1-xBix. The source materials were filled with argon in a quartz ampoule of cone angle <200 at one end at pressure 200 torr. The ampoules were synthesized for 40-50 hrs at 850oC temperature. Five growths of InSb1-xBix bulk semiconductor crystal were carried out at the growth rate varying from 2 to 6 mm/hr and various values of x. Temperature gradient at the solid liquid interface was in the range of 18 oC/cm to 20 oC/cm. The grown ingots were sliced to 450 – 600 mm thickness along the axis and perpendicular to the axis. One growth resulted in p-type semiconductor while the other four resulted in n-type semiconductor. The growth rate of 2 mm/hr show good quality single crystal with maximum mobility up to 44500 cm2/V s at room temperature (300oC), while the higher growth rate produce poor crystal quality (polycrystalline) material. The result of second growth (x=0.05) shows that the material is semiconductor having resistivity 5.45 X 10-4 Ω cm. Linear variation of the Hall voltage with the applied magnetic field shows that the crystal is good semiconductor. The lattice constant of the sample InSbBi-2 found to be changed by 21 Ao as compared to the pure InSb. Calculation of energy band gap from the variation of resistivity with the temperature show reduction of the energy band gap up to 0.138 eV as compared with the energy band gap of the pure InSb (0.172eV) at room temperature. No appreciable change in the parameters tested after 6 months reveals that the material parameter does not change with time.