Electrical characterization of gallium antimonide-based semiconductors for 2--4 micrometer diode laser applications

Deep level transient spectroscopy (DLTS) was used to characterize the band offsets and deep levels in MBE grown GaSb-based materials that are used in 2-4 {dollar}mu{dollar}m laser diode structures. Several deep level traps were found in {dollar}rm Alsb{lcub}x{rcub}Gasb{lcub}1-x{rcub}Assb{lcub}y{rcub}Sbsb{lcub}1-y{rcub}{dollar} (x = 0, 0.5, 0.6, 1.0) including a Ga{dollar}sb{lcub}rm Sb{rcub}{dollar} double acceptor trap and a DX center. Significant progress has also been made in establishing the model for the DX center in this material. The degree of compensation of the donor related DX center by Ga{dollar}sb{lcub}rm Sb{rcub}{dollar} affect where donors are situated, giving preference to one configuration over the many other possible configurations.; One minority trap 320 meV below the conduction band, and six hole traps 24, 76, 108, 122, 224, and 276 meV above the valence band were found in the {dollar}rm Gasb{lcub}0.85{rcub}Insb{lcub}0.15{rcub}Assb{lcub}0.12{rcub}Sbsb{lcub}0.88{rcub}{dollar} using DLTS measurements. It is believed that the minority trap level at 320 meV and the hole trap level at 276 meV originate from the same trap, making it the most efficient non-radiative recombination center.; Extrapolating quantum well emission energies measured at a series of reverse biases with DLTS (based on Boltzmann's approximation) to a point where the approximation is valid, results in a valence band offset of 0.52 eV between {dollar}rm Gasb{lcub}0.81{rcub}Insb{lcub}0.19{rcub}AsSb{dollar} and {dollar}rm Alsb{lcub}0.9{rcub}Gasb{lcub}0.1{rcub}AsSb{dollar} lattice matched to GaSb, rather than 0.38 eV calculated from the difference in average valence band energy interpolated from the binary constituents using bowing parameters.