Defect formation was studied in block epitaxial PbSe : Cl films satura
ted with selenium, prepared by condensation at various temperatures fr
om molecular beams of vapor from a source charge containing 0.4 and 0.
75% of chlorine. Scanning tunnel microscopy and low-temperature tunnel
spectroscopy were used to analyze the surface topography of the films
. Specific features of chlorine transport through the vapor phase are
evaluated.