Room temperature transport measurements on Bridgman-grown p-type CuIn1-xGaxSe2

Room temperature measurements were made of electrical conductivity (sigma), Hall coefficient (R-H) and Seebeck coefficient (alpha) on filamentary samples of p-type CuInSe2 and CuIn1-xGaxSe2 with x <= 0.3, cut from vertically grown Bridgman ingots. Analysis of the results was done on a two-carrier basis, due to the higher ratio of electron to hole mobility (b) in these materials compared to elemental semiconductors. This treatment yielded a preferred b-value of 5 and to lower calculated hole concentrations than (R(H)e)(-1) and higher hole mobilities than R-H sigma, based on a one-carrier interpretation. This effect was particularly marked in p-type samples with a hole concentration below 10(17) cm(-3), where even a few percent of minority electrons can play an important role. (C) 2007 Elsevier B.V. All rights reserved.