Growth and characterization of PbSe and Pb1-xSnxSe on Si (100)

PbSe and Pb(1-x)Sn(x)Se layers, with thicknesses ranging from 1 to 5 mu m, were grown by liquid phase epitaxy on Si (100) substrates using PbSe/BaF(2)/CaF(2) 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 X8 mm(2) substrate area, ternary Pb(1-x)Sn(x)Se 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 mu m spectral range. (C) 1999 American Institute of Physics. [S0021-8979(99)00510-1].