TEMPERATURE-DEPENDENCE OF THE THRESHOLD CURRENT FOR ALGAAS LASERS GROWN BY LOW-TEMPERATURE LPE

In the present work we study the temperature dependence of the thresho ld current density J(th) in straight separate confinement heterostruct ure (SCH) lasers. The laser structures were grown by the low temperatu re liquid phase epitaxy (LT-LPE) technique. The threshold current of t he devices was measured in a wide temperature interval (77-350 K) for conventional and quantum well (QW) lasers. In order to have a better c haracterization of the laser diodes and understanding of the results, theoretical estimations of the temperature dependence of J(th) were pe rformed. The theory takes into account three loss mechanisms: leakage current, non-radiative recombination from the L and X conduction band minima of the active layer material and Auger recombination. The exper imental results fit quite well the theoretical predictions. Moreover, it will be shown that the mayor influencing factor in the threshold cu rrent density-temperature behavior is the leakage current. The relativ ely high. values of the characteristic temperature To obtained, prove that LT-LPE technique is a suitable one for the performance of laser d iodes with a good thermal stability.