High quality InAs0.04Sb0.96/GaAs single crystals with a cutoff wavelength of 12 μm grown by melt epitaxy

The InAs0.04Sb0.96 epilayers with a cutoff wavelength of 12 mu m were successfully grown on semi-insulating (100) GaAs substrates using melt epitaxy (ME). Fourier transform infrared (FTIR) transmission spectra reveal a strongly band gap narrowing for this alloy. A room-temperature band gap of 0.1055 eV is demonstrated via analyzing the temperature dependence of the carrier density for the InAs0.04Sb0.96 layers, which is in good agreement with the value obtained by transmittance measurements. The temperature dependence of energy band gap for InAs0.04Sb0.96/GaAs is studied between 12 K and 300 K by measuring the absorption spectra. An electron mobility of 44,700 cm(2)/Vs with a carrier density of 8.77 x 10(15) cm(-3) at 300 K, an electron mobility of 21,500 cm(2) Ns with a carrier density of 1.57 x 10(15) cm(-3) at 77 K, and a peak electron mobility of 48,000 cm(2)/Vs at 245 K have been achieved for a 100 gm thick epilayer. These results indicate its potential applications for infrared photodetectors and high-speed electron devices.