In order to accurately characterize the photoluminescence from an InAs/AlAsSb multi-quantum well hot carrier absorber, the band structure is generated with an 8 band k·p model utilizing the Naval Research Laboratory’s MultiBands® software tool. The simulated spectra for transitions between the lowest energy electron sub-band and the four lowest hole sub-bands are computed from the optical matrix elements and the calculated band structure. In depth temperature dependent simulations for absorption and photogenerated recombination of electron-hole carriers are compared with the experimental spectra. There is close agreement between simulated and observed spectra in particular, the room temperature e1-hh1 simulated transition energy of 805 meV nearly matches the 798 meV transition energy of the experimental photoluminescence spectra. Also, the expected energy separations between local maxima (p1-p2) in the simulated/experimental spectra have a difference of just 2 meV. The model has a valence band offset of 63 meV which is in general agreement with photoluminescence feature that suggests a valence band offset of 70 meV.
To analyze the ‘hot’ carriers, the photoluminescence spectra is evaluated with three different methods, a linear fit to the high energy portion of the spectra and two methods which utilize either an equilibrium or non-equilibrium generalized Planck relation to fit the whole spectrum. The non-equilibrium fit enables individual carrier temperatures for both holes and electrons. This results in two very different carrier temperatures for holes and electrons: where the hole temperature, Th, is nearly equal to the lattice temperature, TL; while, the electron temperature, Te, is ‘hot’.
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