Identification of quantum confined interband transitions in type-II InAs/GaSb superlattices using polarization sensitive photocurrent spectroscopy

We report on the use of polarization sensitive photocurrent spectroscopy for identifying the participating transitions in type-II InAs/GaSb strained layer superlattice system. Transverse electric and transverse magnetic photocurrents have been measured for both midwave infrared and longwave infrared superlattices, and prominent features have been analyzed to identify different interband transition energies and unambiguously predict the correct ordering of hole minibands. The interband transition energies have also been confirmed with theoretical simulations using empirical pseudopotential method. Order of the participating valence minibands has been determined as: heavy-hole1, light-hole1 and light-hole2, with increase in hole energy. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767358]