Magneto-spectroscopy investigation of InAs/InAsSb superlattices for midwave infrared detection

Raising the operating temperature of the midwave infrared (MWIR) cameras up to 150 K without penalizing the performances of the photodetectors is one of the main challenges of the domain. Moreover, extending the range of detection up to 5  μm brings many advantages. Ga-free InAs/InAsSb superlattice based devices have been recently fabricated and they showed the first realization of these objectives. However, the band parameters (band offsets, effect of strain, effective mass) of this system have not been determined accurately, thus limiting the understanding and the prediction of the electronic properties of the devices. In this work, we determined the relevant parameters via magnetoabsorption measurements performed on dedicated superlattices. Interband magneto-optical transitions lead to an accurate mapping of the Landau levels. The Landau level energies have been calculated using an 8-band k ⋅ p model, and the comparison with the experimental data provided a clear description of the type 2 superlattice miniband structure at 4.2 and 150 K, as well as its MWIR absorbance.