Excitonic Absorption Lines of PbS in a CdS−PbS Composite

Abstract

The spectral dependences of transmission, absorption, and reflection in CdS−PbS semiconductor layers, which are promising for the development of photodetectors and emitters in the region of an atmospheric- transparency window, were studied. It has been established that a series of thin lines are observed in the infrared spectrum on an absorption edge of the narrow-gap phase (PbS). A method for identification of exciton series was used, and exciton-binding energy E_ex, exciton concentration N, and value of valence-band splitting ΔE_v were determined.