TABLE OF CONTENTS Besides adding As or Tl to an InSb lattice, it is also possible to substitute Bi. As a result, a rapid reduction of the bandgap is expected. The basis of the prediction is InBi, which has a bandgap of 1.5 eV. By alloying InBi with InSb, it has been suggested that the bandgap energy of InSbBi could be varied from -1.5 to 0.23 eV. Assuming a linear dependence of the bandgap energy on the alloy composition, InSb 1- xBi x can then be expected to reach a bandgap of 0.1 eV at x = 0.08.
For the growth of the InSbBi alloy, InSb buffer was first grown under the optimum growth conditions determined from the InSb investigations. The growth of InSbBi was then attempted by intruding a small flow of TMBi primarily near the optimum growth condition of InSb. The highest Bi concentration in InSbBi was achieved with the growth temperature of 456 C, growth pressure of 76 Torr, and V/III ratio of 13. The growth rate of this layer was about 1.3 ?m/hr.
The (004) XRD for an as-deposited InSbBi layer on InSb substrate showed two distinct peaks around 28.4 . The X-ray peak corresponding to InSb substrate is observed at an angle of 28.39 . The X-ray peak at an angle of 28.49 is attributed to the InSbBi and clearly distinguished from that of InSb substrate. To confirm that the peak at higher angular position corresponds to the...
