PbSrSe layers and PbSe/PbSrSe multiple quantum well (MQW) structures have been grown on BaF2 (111) substrates by molecular beam epitaxy. The lattice constant of the PbSrSe alloy was determined by x-ray diffraction, and both the refractive index and absorption edge of the PbSrSe alloy with Sr composition up to 0.23 were obtained from Fourier transform infrared transmission spectra at room temperature. MQW structures exhibit strong photoluminescence (PL) in the 3–5 μm wavelength range at room temperature. The PL intensity decreases monotonically with increasing temperature below 230 K.

PbSe and Pb1−xSnxSe layers, with thicknesses ranging from 1 to 5 μm, were grown by liquid phase epitaxy on Si (100) substrates using PbSe/BaF2/CaF2 buffer layers grown by molecular beam epitaxy. Optical Nomarski characterization revealed excellent surface morphologies and good growth solution wipeoffs. Although most PbSe layers were free of cracks over the entire 8×8 mm2 substrate area, ternary Pb1−xSnxSe layers exhibited varying crack densities ranging from zero in the center of samples to over 30 cracks/cm at the edges. High resolution x-ray diffraction (HRXRD) measurements of crack-free PbSe layers showed a residual in-plane tensile strain of 0.21% indicating that most of the 0.74% thermal expansion mismatch strain was absorbed by plastic deformation. HRXRD full width half maxima values of less than 200 arc sec showed that these layers also had high crystalline quality. Fourier transform infrared transmission measurements at room temperature and 110 K showed absorption edges in the range of 270–80 meV, depending on temperature and tin content. This work shows that these materials should be suitable for fabrication of mid-infrared devices covering the 4.6–16 μm spectral range.

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Elimination of threading dislocations in as-grown PbSe film on patterned Si(111) substrate using molecular beam epitaxy Appl.We report results on the incorporation of Bi ͑n type͒ and Tl ͑p-type͒ impurity in PbSe and PbEuSe grown on CaF 2 /Si͑111͒ by molecular beam epitaxy. Bi 2 Se 3 and Tl 2 Se were used as sources of dopants in the growth. Electron concentrations in the low 10 19 cm Ϫ3 range and hole concentrations in the middle 10 18 cm Ϫ3 range have been realized in the PbSe and PbEuSe layers with Eu content up to 3%. Electron and hole mobilities are comparable to those for PbSe and PbEuSe grown on BaF 2 .

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