ELABORATION AND CHARACTERIZATION OF INASSB GROWN ON GASB AND GAAS SUBSTRATES

We study the growth of InAs0.91Sb0.09 lattice matched on GaSb presenting a bandgap of 0.29 eV (4.2 mu m) at 300 K. The layers are grown on (100) GaSb and GaAs substrates at atmospheric pressure in a vertical reactor MOVPE (metal organic vapor phase epitaxy) system using trimethylindium (TMIn), trimethylantimony (TMSb) and arsine (AsH3). We report the results on growth rate and InSb incorporation versus growth parameters as temperature and TMSb partial pressure for different V/III ratios. Carrier density and mobility of InAsSb undoped layers are given. Optical photoconductivity measurements are presented with a wavelength cut off up to 5.4 mu m at 300 K, and the absorption by atmospheric CO2 at 4.25 mu m is clearly detected. The I-V curves of (n)InAsSb/(n and p)GaSb heterojunctions are presented. At room temperature, the dark current for the n/n heterostructure is 70 mu A at -1 V, while the n/p junction is ohmic.