The present invention is embodied in high performance p-type thermoelectric materials having enhanced thermoelectric properties and the methods of preparing such materials. In one aspect of the invention, p-type semiconductors of formula Zn_4-xA_xSb_3-yB_y wherein 0x4, A is a transition metal, B is a pnicogen, and 0y3 are formed for use in manufacturing thermoelectric devices with substantially enhanced operating characteristics and improved efficiency. Two methods of preparing p-type Zn₄Sb₃ and related alloys of the present invention include a crystal growth method and a powder metallurgy method.