Characterization of CuGaTe2 grown by the Tellurization of Cu and Ga in liquid phase Original Research Article

The Hall coefficient between 80 and 300 K and optical absorption coefficient as a function of incident photon energy are studied in single crystal samples of p-type CuGaTe2. The electrical measurements were made on samples that were obtained by vertical Bridgman technique which were later annealed in vacuum and Ga and also those grown by tellurization at different temperatures of Cu and Ga in liquid phase. From the analysis of the Hall data in several non-degenerate samples, it is established that the density of states effective mass of the holes in CuGaTe2 is (1.27±0.02)me. From the optical absorption data, direct band gap that varies from 1.18 to 1.33 eV in degenerate samples, follows the relation The extrapolation in the ideal non-degenerate case gives the estimated value of EG(0) to be 1.19 eV.