Far infrared study of local impurity modes of Boron-doped PbTe

Abstract

PbTe single crystals, doped with B, were grown using the Bridgman method. Far infrared spectra were measured in the temperature range between 10 K and room temperature. The experimental spectra were numerically analyzed, and optical parameters were calculated. Local impurity modes of boron were observed at about 150 and 240 cm(-1). For all samples, after FIR measurements, the content of boron was measured using inductively coupled plasma atomic emission spectrometry. Optical mobility of free carriers was calculated and it was the highest for the sample with only 0.014 at.% of boron in PbTe. A negative photoconductivity effect at 130 K for PbTe + B was also observed.