Techniques for growing p-PbSe0.78Te0.22/n-Pb1-xSnxSe1-xTey/n-PbSe0.78Te0.22 double heterostructures(x up to 0.2 in the liquid growth solution) on (100) BaF2 substrates by liquid phase epitaxy (LPE) are described. Inclusion-free epilayers and good wipeoffs have been consistently achieved using these techniques. Surface morphology of the epilayers is investigated using Nomarski microscopy and atomic force microscopy (AFM). Fourier transform infrared (FTIR) transmission measurements show optical absorption edge energies vary monotonically with tin content and with temperature at an average rate of 0.41 meV per degree in the temperature range of 300 K to 130 K, Tunable diode lasers (TDLs) fabricated from these structures are expected to span a spectral range of 5-7 mu m for x = 5% and 6-9 mu m for x = 12% in this temperature range.