TEMPERATURE-DEPENDENCE OF ELECTRICAL-CONDUCTIVITY AND HALL-EFFECT OF GA2SE3 SINGLE-CRYSTAL

Electrical conductivity (sigma) and Hall coefficient (R(H)) of single crystal grown from the melt have been investigated over the temperatur e range from 398 K to 673 K. Our investigation showed that our samples are p-type conducting. The dependence of Hall mobility an charge carr ier concentration on temperature were presented graphically. The forbi dden energy gap was calculated and found to be 1.79 eV. The ionization energy of impurity level equals 0.32 eV approximately. At 398 K the m obility equals to 8670 cm2 V-1 s-1 and could described by the law mu = aT(n) (n = 1.6) in the low temperature range. In the high temperature range, adopting the law mu = bT(-m) (as m = 1.67), the mobility decre ases. This result indicates that in the low temperature range the domi nant effect is scattering by ionized impurity atoms, whereas in the hi gh temperature range the major role is played by electron scattering o n lattice vibrations (phonons). At 398 K the concentration of free car riers showed a value of about 1.98 x 10(7) cm-3.