InAsSbBi and InSbBi: Potential Material Systems for Infrared Detection

Abstract

InSb_1−x Bi_x (0.01 < × < 0.14) and InAsSbBi quaternary alloys are potentially attractive materials for the development of semiconductor infrared detectors covering the 8–14 μm range [1,2,3].

We report for the first time, MOCVD growth of InSo_1−x Bi_x (0.01 < × < 0.14) and InAs_1−x−y Sb_x Bi_y with 0.5 < × < 0.7 and 0.01 < y < 0.04 on both GaAs and InSb substrates using AsH3, TMSb, TEI and TMBi. Electrical measurements of the undoped InSo_0.99 Bi_0.01 shows a background carrier concentration of approximately 10¹⁶/cm³ and a room temperature mobility of 20,215 cm²/V.sec. To-date, these are the best reported electrical measurements for this ternary alloy.

The formation of a secondary Bi phase and single crystal growth of metallic bismuth-antimony at the surface of InSo_1−x Bi_x which results in deterioration of morphology with increasing values of x is also investigated. A wide range of analytic techniques, including SEM, EDX, electron microprobe and AES have been employed in our surface analysis.