ELECTRICAL-PROPERTIES OF PBTE AND (PBSN)TE SURFACES

Electronic and band properties of PbTe and Pb1-xSnxTe with x = 0.20, 0 .25, and 0.30 have been studied experimentally by a method involving a field effect in electrolytes. The band gaps have been determined. The effective masses of the densities of electron and hole states at the surface in the space-charge region of these materials have also been d etermined. The dispersion relation of the allowed bands near the surfa ce in the PbTe and Pb1-xSnxTe can be described satisfactorily by a par abolic model.