GROWTH AND CHARACTERIZATION OF GASB BULK CRYSTALS WITH LOW ACCEPTOR CONCENTRATION

GaSb bulk single crystals with low acceptor concentration were grown f rom a bismuth solution by the traveling heater method. The result is i soelectronic doping by Bi which gives a variation of the opto-electron ic properties as a function of grown length as well as a pronounced mi croscopic segregation. Photoluminescence spectra at 4K show a decrease of the natural acceptor during growth, which is confirmed by Hall mea surements. The electrical properties of this isoelectronic doped GaSb are hole concentrations and mobilities of N-A - N-D = 1.7 x 10(16) cm( -3) and mu = 870 cm(2)/Vs at room temperature and N-A - N-D = 1 x 10(1 6) cm(-3) and mu = 4900 cm(2)/Vs at 77K, respectively. The lowest p-ty pe carrier concentration measured at 300K is N-A - N-D = 3.3 x 10(15) cm(-3)