High purity InxGa1-xSb single crystals with cutoff wavelength of 7-8 μm grown by melt epitaxy

For the first time, InGaSb single crystals with a cutoff wavelength of 7-8 mu m were successfully grown on GaAs substrates by a new growth technique named melt epitaxy. The band gap of InGaSb layers obviously narrowed compared with those with the same compositions grown by ordinary methods and the longest cutoff wavelength reached 8.3 mu m. High electron mobility of 8.05 x 10(4) cm(2)/Vs and low carrier density of 1 x 10(15) cm(-3) at 77 K were obtained indicating high purity of InGaSb epilayers.