Properties of InAs/(Ga,In)Sb strained layer superlattices grown on the {111} orientations

Following the proposal of the extreme type-II InAs/(Ga,In)Sb strained layer superlattice system by Mailhiot and Smith in 1987 for long wavelength infrared detection, a number of groups have experimentally investigated (100) oriented InAs/(Ga,In)Sb strained layer superlattices and demonstrated that these structures can possess energy gaps in the 8–12 μm range with absorption coefficients comparable to HgCdTe. However, a number of advantages are predicted if these structures are grown on the {111} orientations. In this paper, we present details of our investigation of the growth of InAs/GaSb heterostructures and InAs/(Ga,In)Sb strained layer superlattices on the (111)A and (111)B orientations by molecular beam epitaxy, compared to growth on the (100) orientation. Heterojunction growth and incorporation rates of Sb (As) into InAs (GaSb) on (111)A, (111)B, and (100) orientations have been assessed and implications for growth and optical properties of InAs/(Ga,In)SB strained layer superlattices are discussed. GaSb/InAs and InAs/GaSb interfaces on the (111)B orientation are investigated by x-ray photoelectron spectroscopy, and the structural quality of InAs/(Ga,In)Sb strained layer superlattices are investigated by x-ray diffraction.