TEMPERATURE-DEPENDENCE OF THRESHOLD CURRENT FOR DOUBLE-HETEROJUNCTION LASERS

The temperature dependence of the threshold current has been examined for the double-heterojunction lasers (AlGa)As, (InGa) (AsP)/InP, and (InGaAs)/(InGa)P with emission wavelengths between 0.8 and 1.4 μm. For all lasers studied, the threshold current density was found to follow the exponential relationship Jth(T) ∝ exp(T/T0), where the constant T0 was found to be directly related to the energy-band-gap step, ΔEg, between the recombination region and the adjacent confining layers. The value of T0 was found experimentally to obey the relationship T0=AΔEg, with the constant A having values between 200 and 300 °K/eV for the three types of lasers studied.