Valence band states in an InAs/AlAsSb multi-quantum well hot carrier absorber

In this study, detailed temperature dependent simulations for absorption and photogenerated recombination of hot electrons are compared with experimental data for an InAs/AlAsSb multi-quantum well. The simulations describe the actual photoluminescence (PL) observations accurately; in particular, the room temperature e1-hh1 simulated transition energy of 805 meV closely matches the 798 meV transition energy of the experimental PL spectra, a difference of only 7 meV. Likewise, the expected energy separations between local maxima (p1-p2) in the simulated/experimental spectra have a difference of just 2 meV: a simulated energy separation of 31 meV compared to the experimental value of 33 meV. Utilizing a non equilibrium generalized Planck relation, a full spectrum 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' (i.e., Te > TL). Also, by fitting the experimental spectra via three different methods a 'hot' carrier temperature is associated with electrons only; all three methods yield similar 'hot' carrier temperatures.