Experimental and Theoretical Analysis οf PbTe-CdTe Solid Solution Grown by Physical Vapour Transport Method

Abstract

Bulk monocrystals of Pb 1-x Cd x Te, with the Cd content x up to 0.11, were grown by physical vapour transport method. The structural, electrical and optical properties of these ternary crystals were studied experimentally and theoretically. All investigated samples exhibit rock-salt structure and high crystal quality, which was confirmed by X-ray rocking curve width parameter of about 100 arcsec. The decrease of the lattice parameter with increasing Cd content x was found experimentally, in agreement with ab initio calculations. The band structures of Pb 1-x Cd x Te mixed crystals for x values up to 0.2 were calculated using tight binding approach. The calculated band gap in the L-point increases with the Cd content in qualitative agreement with photoluminescence measurements in the infrared. For all studied Pb 1-x Cd x Te samples, the Hall effect and electrical conductivity measurements, performed in the temperature range from 4 to 300 K, revealed p-type conductivity.