Relation entre proprietes electriques et defauts de reseau dans ZnSiAs2. Partie II—analyse de la mobilite

Abstract The Hall mobilities of ZnSiAs 2 were measured and analyzed in the temperature range 20–300 K or 77–300 K depending on crystal type. For temperatures higher than 100 K, the behavior of majority carriers can be explained in most cases by the cumulative action of lattice scattering and ionized impurity scattering. The theoretical values of these sample mobilities can be calculated taking into account the impurities already ionized (resulting from compensation) and those created by thermal ionization in the temperature range studied. Annealing effects under zinc or arsenic vapor depend on these two quantities. Below 30 K, some samples exhibit a strong decrease of the mobility which may be due to impurity band conduction. If all types of impurity are considered, ZnSiAs 2 crystals show a great number of defects, generally larger than 10 18 cm −3 .