TRANSPORT-PROPERTIES OF LIGHTLY DOPED COSB3 SINGLE-CRYSTALS

CoSb3 single crystals with low hole concentration (down to 1C(17) cm(- 3)) at 300 K and 2.6 X 10(16) cm(-3) at 90 K) and the highest observed value of the room-temperature hole mobility (the value is up to 6000 cm(2)/V s, i.e., up to about 1.8 times higher than maximum values prev iously reported) were grown. The observed temperature dependence of th e Hall coefficient is explained assuming the existence of an acceptor impurity band and an additional deep acceptor level. The values of the activation energies of the shallow and deep accepters, their concentr ations, as well as the concentration of the compensating donors were c alculated. It is shown that the scattering due to polar optical phonon s and nonpolar optical phonons is most important in the high-temperatu re region. The value of the valence-band deformation potential is esti mated.