High Lattice Match Growth of InAsSb Based Materials by Molecular Beam Epitaxy**Supported by the National Natural Science Foundation of China under Grant Nos 11474248, 61176127, 61006085, 61274013 and 61306013, the Key Program for International S&T Cooperation Projects of China under Grant No 2011DFA62380, and the Ph.D. Programs Foundation of the Ministry of Education of China under Grant No 20105303120002.

Abstract

High lattice match growth of InAsSb based materials on GaSb substrates is demonstrated. The present results indicate that a stable substrate temperature and the optimal flux ratios are of critical importance in achieving a homogeneous InAsSb based material composition throughout the growth period. The quality of these epilayers is assessed using a high-resolution x-ray diffraction and atomic force microscope. The mismatch between the GaSb substrate and InAsSb alloy achieves almost zero, and the rms surface roughness of InAsSb alloy-achieves around 1.7 Å over an area of 28 μm × 28 μm. At the same time, the mismatches between GaSb and InAs/InAs0.73Sb0.27 superlattices (SLs) achieve approximately 100 arcsec (75 periods) and zero (300 periods), with the surface rms roughnesses of In As/InAs0.73Sb0.27 SLs around 1.8 Å (75 periods) and 2.1 Å (300 periods) over and area of 20 μm × 20 μm, respectively. After fabrication and characterization of the devices, the dynamic resistance of the n-barrier-n InAsSb photodetector near zero bias is of the order of 106 Ω·cm2. At 77K, the positive-intrinsic-negative photodetectors are demonstrated in InAsSb and InAs/InAsSb SL (75 periods) materials, exhibiting fifty-percent cutoff wavelengths of 3.8 μm, and 5.1 μm, respectively.