PbTe and Pb0.8Sn0.2Te epitaxial films on cleaved BaF2 substrates prepared by a modified hot-wall technique

PbTe and Pb0.8Sn0.2Te epitaxial films have been grown on cleaved BaF2 substrates by a modified hot-wall technique. Relatively fast growth rates of 3–5 μm/h have been used to prepare high-quality epitaxial films between 5 and 13 μm in thickness. Both p- and n-type films have been grown by temperature control of a separate Te reservoir included in the apparatus. Carrier concentrations and mobilities in the orders of 2×1016–7×1017/cm3 and 1–3.3×104 cm2/V sec, respectively, have been measured in the as-grown films at 77 K. Pb0.8Sn0.2Te homojunction and PbTe-Pb0.8Sn0.2Te heterojunction layers have been prepared. Diode elements engraved in the layers by mesa etching have shown R0A products between 19 and 38 Ω cm2 for heterojunction structures at 77 K.