Lead tin telluride

Lead tin telluride, also referred to as PbSnTe or Pb_1-xSn_xTe, is a ternary alloy of lead, tin and tellurium, generally made by alloying either tin into lead telluride or lead into tin telluride. It is a IV-VI narrow band gap semiconductor material.

The band gap of Pb_1-xSn_xTe is tuned by varying the composition(x) in the material. SnTe can be alloyed with Pb (or PbTe with Sn) in order to tune the band gap from 0.29 eV (PbTe) to 0.18 eV (SnTe). It is important to note that unlike II-VI chalcogenides, e.g. cadmium, mercury and zinc chalcogenides, the band gap in Pb_1-xSn_xTe does not changes linearly between the two extremes. In contrast, as the composition (x) is increased, the band gap decreases, approaches zero in the concentration regime (0.32-0.65 corresponding to temperature 4-300 K respectively) and further increases towards bulk band gap of SnTe. Therefore, the lead tin telluride alloys have narrower band gaps than their end point counterparts making lead tin telluride an ideal candidate for mid infrared, 3-14 μm opto-electronic application.