Intrinsic Optical Absorption and the Radiative Recombination Lifetime in PbS

The intrinsic optical absorption spectrum of PbS crystals has been measured. The absorption coefficients range from about 10 cm^-1 to 10⁵ cm^-1 giving continuous data through the band edge. At 300^∘{}K the data indicate a direct transition energy of 0.41 ev and an indirect transition energy of 0.37 ev. The radiative recombination lifetime for PbS calculated from the absorption data is 63 microseconds at 300^∘{}K.