Copper Indium Gallium.

Filamentary samples were cut from ingots of the chalcopynte semiconductor CuIn1-x,GaxSe2, grown by a vertical Bridgman method for compositions x = 0, 0.2, and 0.3. On these, room-temperature measurements were made of thermoelectric power (alpha), Hall coefficient (RH), and electrical conductivity (sigma). Analysis of the measured results was made on a two-carrier basis, taking the minority electrons into account. Assuming dominant acoustic lattice scattering and an effective hole mass ratio, m p/m0 = 0.7, the only common acceptable value for the electron-to-hole mobility ratio, b, was found to be b = 5, for all filamentary samples. Using this value, hole concentrations were found to be lower than those derived from a one-carrier model, and hole mobilities were correspondingly higher. The mobilities in quaternary samples were lower than those in the ternaries. Furthermore, the hole concentrations were much higher in the quaternary filaments cut from the end of the grown ingots than from the middle