STP911: Refractive Index of Ternary and Quaternary Compound Semiconductors Below the Funadmental Absorption Edge: Linear and Nonlinear Effects

    Jensen, B
    Boston University, Boston, Mass.

    Torabi, A
    Boston University, Boston, Mass.

    Pages: 19    Published: Jan 1985


    Abstract

    The index of refraction n is calculated as a function of frequency and mole fraction x for the following compounds: Hg1−xCdxTe, AlxGa1−xAs, and In1−xGaxAsyP1−y lattice matched to InP. Lattice matching of In1−xGaxAsyP1−y to InP requires that x = 0.466 y. The theoretical result for the refractive index is obtained from a quantum mechanical calculation of the dielectric constant of a compound semiconductor. It is given in terms of the basic material parameters of band gap energy, effective electron mass mn, effective heavy hole mass mp, spin orbit splitting energy, lattice constant, and carrier concentration ne or p for n-type or p-type materials, respectively. If these quantities are known as functions of mole fraction x, there are no adjustable parameters involved. A negative change in the refractive index near the fundamental absorption edge is predicted on passing radiation through a crystal if the change in carrier concentration of the initially unoccupied conduction band is assumed proportional to internal intensity I. Comparison of theory with experimental data is given.

    Keywords:

    Optical constants, optical materials, refractive index, semiconductors


    Paper ID: STP29008S

    Committee/Subcommittee: F01.19

    DOI: 10.1520/STP29008S


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