Temperature Dependence of Thermal Conductivity and Boundary Resistance in THz Quantum Cascade Lasers

We measured the lattice temperature distribution, the cross-plane thermal conductivity , and the thermal boundary resistance (TBR) of the As quantum cascade lasers (QCLs) operating at 2.83 THz in the heat sink temperature range 45-300 K. This information was extracted from the analysis of microprobe band-to-band photoluminescence in QCLs operating in continuous wave. Both and TBR decrease monotonically at increasing temperature, the main influence on arising from the high density of interfaces.