Study of the Ga doped In (1-x) GaxSb (x= 0.10, 0.15, 0.25) crystals' the compositional, structural, electrical, and the microstructures properties: Growth by the VDS-process (original) (raw)

Novel vertical directional solidification process (VDS-process) has been constructed for growth of the III-V detached crystals. Research aim is to grow the gallium ("Ga") doped In (1-x) GaxSb (x=0.10, 0.15, 0.25) ingots. The comprehensive characterization of the composition, structure, electrical, microstructure and the thermoelectric properties by tuning the stoichiometry are studied. The doping in pristine InSb decreased the carrier mobility of the binary InSb ingots from ~6.05x10 4 cm 2 /V.sec to In(1-x)GaSb ~ 1.241x10 4 , 9.01x10 3 , and 2.436x10 3 cm 2 /V.sec, and the resistivity from 3.0x10-3 Ω.cm marginally reduced to 2.98, 2.58, and 1.69 x10-3 Ω.cm. Remarkably, the carrier concentration, increased from ~3.8x10 16 cm 3 to ~1.89, 2.29, and 3.15 x10 18 cm 3 and increase in dislocation density from ~ 962cm-2 in to ~1.21, 6.94 and 9.93x10 3 cm-2. The "Ga" doping tailored the band gap of InSb from 0.169eV to 0.2011, 0.2605 and 0.3011eV, and the increased FWHM from 65arcsec InSb to 103, 124 and 145arcsec for the respective growths. The binary InSb perfect single crystal converted to the perfect ternary crystal and decreased XRD peak intensity of the (022) growth direction by doping "Ga" into InSb. To add, the composition% have been exhibited the point defects and decreased the mobility by one order by doping "Ga", while the electrical resistivity changes marginally. The carrier concentration increased two fold; it promotes increase in the thermo electric power factor and enhancement in ZT value. The "Ga" doping forms the second phase of GaSb at the grain boundaries, which reduces the thermal conductivity, increase dislocations, and carrier concentration. The Ga doping, the electron transport enhances, and is potential for the thermoelectric (TE) materials.