| Crystal Research and Technology |
We have reported narrowed band gap InAsSb single crystals with cut off wavelength of 8-12 µm grown by a new method of Melt Epitaxy (ME) (GAO et al. 1999). In this paper, we firstly present the improvement of low temperature mobility of the InAsSb epilayers with cut off wavelength of 12.5 µm by annealing treatment. The electrical properties were investigated by Van der Pauw measurements at 300 K and 77 K. After an annealing treatment for 11 hours, an electron mobility of 4.83 x 104 cm2/Vs and a carrier density of 8 x 1015 cm-3 have been obtained for an InAs0.04Sb0.96 epilayer at 77 K. This is the best result so far for the InAsSb materials with cut off wavelength of 8-12 µm. The mechanism of the improvement of the electrical properties for this material after annealing treatment was studied by observing the etch pits on the surface of the sample before and after heat treatments.
Keywords: InAsSb, long wavelength, annealing treatment, electron mobility, etch pit, Sb vacancy