Anisotropic Electrical Properties of GeSe

Vapour grown p‐type single crystals of Ge1+xSe, in which x is of the order less than 0.005 are prepared. The crystals include donors and acceptors. From the anisotropy of the electrical resistivity and the Hall coefficient together with the thermoelectric power in the temperature range of 78 to 300 K, the effective masses of holes along the a‐, b‐, and c‐crystallographic axes are obtained to 0.20m, 0.37m, and 6.2m, respectively, where m is the electron mass. The donor level lies 0.17 eV above the valence band, with a concentration in the range of (1.74 to 2.94) × 1024 m−3 according to the variation of x. The concentration of the acceptors is estimated to 3 × 1024 m−3.