Reflectivity and Optical Constants of Indium Arsenide, Indium Antimonide, and Gallium Arsenide

The reflectivities of indium arsenide, indium antimonide, and gallium arsenide were measured at nearly normal incidence from 2050 A to 15 \ensuremath{\mu} at room temperature. The optical constants were computed from these data in the range 0-6.0 ev using the dispersion relation between the phase and the magnitude of the reflectivity. The reflectivities obtained show peaks near 2.5 and 5.0 ev, with splitting of the lower maxima into two smaller peaks whose separations are 0.35, 0.50, and 0.20 ev, respectively, for the three materials. The imaginary part of the reciprocal of the dielectric constant appears to have a maximum beyond 6.0 ev, the magnitudes of this quantity at 6.0 ev being 1.0 for indium arsenide, 1.7 for indium antimonide, and 0.8 for gallium arsenide. These values are uncertain because of the effect of extrapolating the reflectivity to energies above 6.0 ev.