1.College of Science,Harbin University of Science and Technology;2.State Key Laboratories of Transducer Technology,Shanghai Institute of Technical Physics;3.State Key Laboratory of Infrared Physics,Shanghai Institute of Technical Physics
The cutoff wavelengths of short-wave infrared photodetectors with high indium composition InGaAs films are beyond 1.7 μm, attracting much attention owing to their important applications. The effects of molecular beam epitaxy growth parameters on the properties of high indium InGaAs materials have been investigated in this paper. The growth temperature, V/III ratio and arsenic dimers of In0.74Ga0.26As materials were investigated and adjusted to optimize the peak intensity of photoluminescence and X-ray diffraction measurements, as well as background carrier concentration and mobility. Results show that moderate growth temperatures and V/III ratios are needed for the growth to improve the lattice quality, reduce the non-radiation recombination and decrease the background impurity concentration. The In0.74Ga0.26As materials grown using As2 dimers show better material quality than those using As4 dimers. For the material grown at 570 ℃, As2 dimers and V/III ratio of 18, relatively strong photoluminescence and X-ray diffraction peak intensity have been achieved. At room temperature and 77 K, the background carrier concentrations were 6.3×1014 cm-3 and 4.0×1014 cm-3, while the mobilities were 13400 cm2/Vs and 45160 cm2/Vs, respectively.