Intersubband optoelectronics in the InGaAs/GaAsSb material system

In this article the authors report on a novel material system for optoelectronic intersubband devices. Superlattices of In0.53Ga0.47As/GaAs0.51Sb0.49 were grown by molecular beam epitaxy. Layer thickness and quality was investigated by high-resolution x-ray diffraction measurements and high-resolution transmission electron microscopy images. Intersubband absorption measurements on In0.53Ga0.47As/GaAs0.51Sb0.49 superlattices, revealed at room temperature transition energies from 213 to 107 meV for In0.53Ga0.47As well widths of 4.5-11.5 nm at room temperature. These results were used to fit parameters for self-consistent superlattice band structure calculations. Finally, quantum cascade lasers with an emission wavelength of 11.3 mu m and quantum well infrared photodetectors with a peak response near 5.5 mu m were realized in this material system. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3276432]