Study of optical and electrical properties of AlxGa1-xSb grown by metalorganic chemical vapor deposition

AlxGa1-xSb films in the regime 0 less than or equal to x less than or equal to 0.25 have been grown by metalorganic chemical vapor deposition on GaAs and GaSb substrates using TMA1, TMGa, and TMSb precursors. We report growth conditions and film properties including the effect of V/III ratio and gro wth temperature on electrical and optical properties. Growth temperatures i n the range of 520 degreesC and 680 degreesC and V/III ratios from 1 to 5 h ave been investigated. All epilayers grown exhibit p-type behavior. The mob ility decreases and the carrier concentration increases sharply when a smal l amount of Al is incorporated into GaSb. The sharp cutoff and Fabry-Perot oscillations of the transmission spectra of the AlGaSb layers confirm the h igh quality of the films. The principle photoluminescence features observed are attributed to bound exciton and donor-acceptor transitions with FWHM c omparable to the best values reported elsewhere.