PHOTOLUMINESCENCE OF INASBI AND INASSBBI GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY

Infrared photoluminescence (PL) from InAsBi and InAsSbBi epitaxial layers grown by atmospheric pressure organometallic vapor phase epitaxy has been studied. The PL from ternary InAsBi was investigated for Bi concentrations of ≤2.3 at. %. The peak energy decreases at a rate of 55 meV/at. % Bi with increasing Bi concentration. A study of the transmission spectra of these Bi-containing alloys confirms the above result. The PL peak is assigned to near band edge emission for InAsBi. The value of dEg/dx=-55-meV/at. % Bi is more than double the previously reported theoretical prediction for the band gap of InAsBi. The PL for the quaternary layer of InAsSbBi is also studied for Sb concentrations of <10 at. % and Bi concentrations of ≤1.5 at. %. Bi incorporation in InAs1-xSbx(0.07<x<0.10) reduces the PL peak energy at a rate of 46-meV/at. % Bi. These results imply that incorporation of only a few percent of Bi is required in InAs 0.35Sb0.65 to achieve a band gap of 0.1 eV, equivalent to a wavelength of 12 μm, desired for infrared detector applications.