Low temperature mobility controlled by charged dislocations and neutral defects in Pb1−xEuxSe layers grown by MBE

Electrical properties of Pb1−xEuxSe thin films grown by MBE on two different substrates with varying concentrations of Eu were studied. The electrical measurements were made in the temperature range of 4–300 K. The samples deposited on Si substrate (111) using CaF2 buffer layer are n-type. Those directly deposited on BaF2 substrate (111) are all p-type. For europium compositions less than 4%, acoustic phonons, polar optical phonons and neutral impurities mechanisms scattering govern the temperature variations of Hall mobility. Beyond this value of the europium composition, and at low temperature, scattering by charged dislocations becomes the most dominant mechanism.