IMPURITY CONDUCTION IN CADMIUM SULFIDE AT LOW TEMPERATURES

Impurity conduction has been investigated in three types of cadmium sulfide crystals, that is, Cl-doped cadmium sulfide, undoped cadmium sulfide grown from the vapour phase, and undoped cadmium sulfide grown by the melt. The crystals of Cl-doped cadmium sulfide exhibit the characteristics of impurity conduction at low temperatures which are similar to those of n-type germanium and n-type silicon: A metallic impurity conduction occurs above the excess donor concentration of 2×1018 cm-3. The concentration range between 4×1016 cm-3 and 2×1018 cm-3 is intermediate between metallic type and non-metallic one. A negative magnetoresistance effect is observed at the excess donor concentrations above 2×1018 cm-3 in the temperature range from 1.5°K to 4.2°K. © 1968, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.