PHOTOREFLECTANCE MEASUREMENTS OF THE E(1) AND E(1)-TRANSITIONS IN IN1-XALXSB EPILAYERS(DELTA(1) OPTICAL)

Photoreflectance measurements of the E1 and E1 + DELTA1 optical transi tions in epilayers of In1-xAlxSb (0 less-than-or-equal-to x less-than- or-equal-to 0.55) are reported. These are the first reported measureme nts on homogeneous epilayers grown on (001)InSb. The bowing parameters for these transitions (0.752 eV and 0.723 eV respectively) were found to be almost a factor of two higher than those reported almost 20 yea rs ago by Isomura et al. on bulk samples. The present results are more consistent with their predicted value of 0.99 eV. It is believed that inhomogeneities in the bulk samples could have resulted in an incorre ct determination of the bowing parameter. The samples used in this stu dy were homogeneous single crystal epilayers.