Infrared Studies of the (1-x) PbTe-(x) PbSnS_2 System

摘要

In this work we report on the infrared properties of the thermoelectric (1-x)PbTe-xPbSnS_2 system with x=0.03, 0.06, 0.11 and 0.33. The results obtained by the analysis of the reflectivity spectra are discussed together with the structural and morphological characteristics obtained by XRD and SEM-EDS measurements. The system was found macroscopically homogeneous for x=0.03 and x=0.06 and phase separated for x=0.11 and x=0.33. The analyzed ～150cm~(-1) PbS impurity mode demonstrated a composition close to the PbTe_(0.98)S_(0.02) for the major phase. The incorporation of PbSnS_2 causes a reduction in plasma frequency (decrease in carrier frequency concentration) and an increase in carrier mobility.