We compare the electrical power dependence of the lattice temperature and the electronic temperature of GaAs/AlxGa1-xAs THz quantum cascade lasers (QCLs) with different active region schemes, as extracted by the analysis of microprobe band-to-band photoluminescence experiments. Thermalized non-equilibrium distributions are found in all classes of QCLs. While in the case of bound-to-continuum structures all subbands share the same temperature, the upper laser level of active regions based on the resonant-phonon scheme heats up by ΔT ~ 100 K with respect to lower energy levels. The comparison among samples with different Al mole fractions show that the use of smaller x values leads to larger electronic temperatures.
|Autori interni:||SPAGNOLO, Vincenzo Luigi|
|Titolo:||Hot Electrons in THz Quantum Cascade Lasers|
|Rivista:||JOURNAL OF INFRARED, MILLIMETER, AND TERAHERTZ WAVES|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||10.1007/s10762-013-9979-1|
|Appare nelle tipologie:||1.1 Articolo in rivista|