Temperature dependence of the threshold current in quantum-well WGM lasers (2.0–2.5 $\mu$m)

The temperature dependence of the threshold current and emission spectra of disk-shaped quantum-well whispering-gallery mode (WGM) lasers is studied in the temperature range of 80–463 K in which the laser emission wavelength increases from 2 to 2.5 $\mu$m. It is shown that lasing is observed up to 190$^\circ$C. Radiative recombination is dominant up to a temperature of 300 K, and nonradiative Auger recombination, in which a recombining electron gives energy to another electron, is so at higher temperatures. The spin-orbit split-off valence subband is not involved in recombination processes, which is attributed to mechanical compression of the quantum-well material.